Trial Outcomes & Findings for Study of GSK3359609 and Pembrolizumab in Programmed Death Receptor 1-ligand 1 (PD-L1) Positive Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma (NCT NCT04128696)

NCT ID: NCT04128696

Last Updated: 2024-07-10

Results Overview

OS was defined as the time from the date of randomization to the date of death due to any cause. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median OS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

• Recruitment status: TERMINATED
• Study phase: PHASE3
• Target enrollment: 315 participants
• Primary outcome timeframe: Up to approximately 16 months
• Results posted on: 2024-07-10

Participant Flow

A total of 315 participants with recurrent or metastatic head and neck squamous cell carcinoma/cancer (HNSCC) were enrolled in this study.

Recruitment in the study was stopped following review of interim safety and efficacy data by the Independent Data Monitoring Committee, after a pre-specified futility analysis. A Dear Investigator Letter (DIL) was issued to stop screening/randomization of further subjects to the study.

Participant milestones

Measure	Participants Receiving Feladilimab and Pembrolizumab Participants were administered feladilimab (GSK3359609-humanized anti-ICOS immunoglobulin G4 \[IgG4\] monoclonal antibody \[mAb\]) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an intravenous (IV) infusion once every three weeks (Q3W).	Participants Receiving Placebo and Pembrolizumab Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Overall Study STARTED	158	157
Overall Study Modified Intent to Treat (mITT) Population	157	156
Overall Study Safety Population	159	156
Overall Study COMPLETED	115	98
Overall Study NOT COMPLETED	43	59

Reasons for withdrawal

Measure	Participants Receiving Feladilimab and Pembrolizumab Participants were administered feladilimab (GSK3359609-humanized anti-ICOS immunoglobulin G4 \[IgG4\] monoclonal antibody \[mAb\]) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an intravenous (IV) infusion once every three weeks (Q3W).	Participants Receiving Placebo and Pembrolizumab Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Overall Study Lost to Follow-up	3	7
Overall Study Withdrawal by Subject	12	11
Overall Study Study Closed/Terminated	26	38
Overall Study Physician Decision	2	3

Baseline Characteristics

Study of GSK3359609 and Pembrolizumab in Programmed Death Receptor 1-ligand 1 (PD-L1) Positive Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

Baseline characteristics by cohort

Measure	Participants Receiving Feladilimab and Pembrolizumab n=158 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=157 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Total n=315 Participants Total of all reporting groups
Age, Customized 18-64 years	95 Participants n=5 Participants	79 Participants n=7 Participants	174 Participants n=5 Participants
Age, Customized ≥65-84 years	62 Participants n=5 Participants	76 Participants n=7 Participants	138 Participants n=5 Participants
Age, Customized ≥85 years	1 Participants n=5 Participants	2 Participants n=7 Participants	3 Participants n=5 Participants
Sex: Female, Male Female	29 Participants n=5 Participants	31 Participants n=7 Participants	60 Participants n=5 Participants
Sex: Female, Male Male	129 Participants n=5 Participants	126 Participants n=7 Participants	255 Participants n=5 Participants
Race/Ethnicity, Customized Asian - Central/South Asian Heritage	2 Participants n=5 Participants	0 Participants n=7 Participants	2 Participants n=5 Participants
Race/Ethnicity, Customized Asian - East Asian Heritage	19 Participants n=5 Participants	22 Participants n=7 Participants	41 Participants n=5 Participants
Race/Ethnicity, Customized Asian - Japanese Heritage	12 Participants n=5 Participants	7 Participants n=7 Participants	19 Participants n=5 Participants
Race/Ethnicity, Customized Black or African American	4 Participants n=5 Participants	2 Participants n=7 Participants	6 Participants n=5 Participants
Race/Ethnicity, Customized Missing	3 Participants n=5 Participants	6 Participants n=7 Participants	9 Participants n=5 Participants
Race/Ethnicity, Customized Mixed White Race	1 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants
Race/Ethnicity, Customized Multiple	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized White - Arabic/North African Heritage	4 Participants n=5 Participants	1 Participants n=7 Participants	5 Participants n=5 Participants
Race/Ethnicity, Customized White - White/Caucasian/European Heritage	111 Participants n=5 Participants	118 Participants n=7 Participants	229 Participants n=5 Participants
Race/Ethnicity, Customized Native Hawaiian or Other Pacific Islander	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants

PRIMARY outcome

Timeframe: Up to approximately 16 months

Population: mITT: All randomized participants, whether or not randomized intervention was administered, excluding those who were first dosed or randomized after the date of DIL requesting immediate discontinuation of feladilimab /placebo. This analysis was based on the study intervention to which the participant was randomized. All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

OS was defined as the time from the date of randomization to the date of death due to any cause. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median OS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Overall Survival (OS) in the Programmed Death Receptor-ligand 1 (PD-L1) Combined Positive Score (CPS) ≥1 Population	44.1 Week Interval 35.9 to The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.	NA Week Interval 52.4 to The median was not reached at the time of data cut off. The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.

PRIMARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

OS was defined as the time from the date of randomization to the date of death due to any cause. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median OS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
OS in the PD-L1 Expression High (CPS ≥20) Population	42.1 Week Interval 25.4 to The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.	NA Week Interval 52.4 to The median was not reached at the time of data cut off. The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.

PRIMARY outcome

Timeframe: Up to approximately 16 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

PFS per RECIST version (v)1.1 was defined as the time from the date of randomization to the date of first documented disease progression or death due to any cause, whichever occurs first. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median PFS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Progression-free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors (RECIST) in the PD-L1 CPS ≥1 Population	10.1 Week Interval 9.1 to 15.0	16.0 Week Interval 14.3 to 26.1

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

PFS per iRECIST was defined as the interval of time from the date of randomization to the date of the first documented disease progression confirmed consecutively per iRECIST based on investigator assessment, or death due to any cause, whichever occurs first. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median PFS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
PFS Per Immune-based RECIST (iRECIST) in the PD-L1 CPS ≥1 Population	13.0 Week Interval 9.1 to 15.1	21.4 Week Interval 15.6 to 27.0

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

PFS per RECIST v1.1 was defined as the time from the date of randomization to the date of first documented disease progression per RECIST v1.1. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median PFS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
PFS Per RECIST in the PD-L1 CPS ≥20 Population	13.0 Week Interval 8.6 to 26.1	21.1 Week Interval 15.6 to 32.9

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

PFS per iRECIST was defined as the interval of time from the date of randomization to the date of the first documented disease progression confirmed consecutively per iRECIST based on investigator assessment, or death due to any cause, whichever occurs first. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells. Kaplan-Meier estimate for the median PFS is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
PFS Per iRECIST (iPFS) in the PD-L1 CPS ≥20 Population	13.1 Week Interval 8.6 to 26.7	26.7 Week Interval 20.1 to 32.9

SECONDARY outcome

Timeframe: 12 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

Milestone OS rate at 12 months was estimated using the Kaplan-Meier method. Associated 95% confidence intervals are estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Milestone OS Rate at 12 Months in the PD-L1 CPS ≥1 Population	44.0 Percentage of participants Interval 30.0 to 58.0	68.0 Percentage of participants Interval 57.0 to 77.0

SECONDARY outcome

Timeframe: 24 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were to be analyzed. Data for this endpoint were not collected as all participants were on the study for \< 24 months, the maximum duration of follow-up was approximately 16 months.

Milestone OS rate at 24 months was not evaluated. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 12 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

Milestone OS rate at 12 months was estimated using the Kaplan-Meier method. Associated 95% confidence intervals are estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Milestone OS Rate at 12 Months in the PD-L1 CPS ≥20 Population	46.0 Percentage of participants Interval 28.0 to 63.0	88.0 Percentage of participants Interval 76.0 to 94.0

SECONDARY outcome

Timeframe: 24 months

Population: Participants with PD-L1 CPS ≥20 in the mITT population were to be analyzed. Data for this endpoint were not collected as all participants were on the study for \<24 months, the maximum duration of follow-up was approximately 16 months.

Milestone OS rate at 24 months was not evaluated. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

ORR per RECIST v1.1 was defined as the proportion of the participants who have a complete response (CR) or partial response (PR) as the best overall response per RECIST v1.1 based upon investigator assessment. As a randomized double-blind study in which primary endpoints are OS and PFS, the confirmation of CR and PR was not required. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Overall Response Rate (ORR) Per RECIST v1.1 in the PD-L1 CPS ≥1 Population	19.7 Percentage of Participants Interval 13.8 to 26.8	25.0 Percentage of Participants Interval 18.4 to 32.6

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

ORR per RECIST v1.1 was defined as the proportion of the participants who have a CR or PR as the best overall response per RECIST v1.1 based upon investigator assessment. As a randomized double-blind study in which primary endpoints are OS and PFS, the confirmation of CR and PR was not required. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
ORR Per RECIST v1.1 in the PD-L1 CPS ≥20 Population	20.0 Percentage of Participants Interval 11.4 to 31.3	33.3 Percentage of Participants Interval 22.4 to 45.7

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

DCR per RECIST v1.1 based upon investigator assessment, was defined as the percentage of participants with a best overall response of CR or PR at any time plus stable disease (SD) meeting the minimum time of 15 weeks. A status of SD≥15 weeks will be assigned if the follow-up disease assessment has met the SD criteria at least once after the date of randomization at a minimum of 14 weeks (98 days) considering a one-week visit window. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Disease Control Rate (DCR) Per RECIST v1.1 in the PD-L1 CPS ≥1 Population	33.1 Percentage of Participants Interval 25.8 to 41.1	44.9 Percentage of Participants Interval 36.9 to 53.0

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

DCR per RECIST v1.1 based upon investigator assessment, was defined as the percentage of participants with a best overall response of CR or PR at any time plus stable disease (SD) meeting the minimum time of 15 weeks. A status of SD≥15 weeks will be assigned if the follow-up disease assessment has met the SD criteria at least once after the date of randomization at a minimum of 14 weeks (98 days) considering a one-week visit window. Rate and associated 2-sided 95 percent Exact (Clopper-Pearson) Confidence Intervals are provided for each treatment arm which are unadjusted. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
DCR Per RECIST v1.1 in the PD-L1 CPS ≥20 Population	37.1 Percentage of Participants Interval 25.9 to 49.5	55.1 Percentage of Participants Interval 42.6 to 67.1

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with a best overall response of CR or PR in the mITT population with PD-L1 CPS ≥1 are presented.

DoR per RECIST v1.1 is defined as the time from first documented evidence of CR or PR until first documented disease progression per RECIST v1.1 based upon investigator assessment or death due to any cause, whichever occurs first, among participants who demonstrated CR or PR as the best overall response per RECIST v1.1. Kaplan-Meier estimate for the median DoR is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=31 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=39 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Duration of Response (DoR) Per RECIST v1.1 in the PD-L1 CPS ≥1 Population	NA Weeks The median was not reached at the time of data cut off. The upper and lower limit of the 95% CI was not calculable from the available data at the time of data cut off.	NA Weeks Interval 20.6 to The median was not reached at the time of data cut off. The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with a best overall response of CR or PR in the mITT population with PD-L1 CPS ≥20 are presented.

DoR per RECIST v1.1 is defined as the time from first documented evidence of CR or PR until first documented disease progression per RECIST v1.1 based upon investigator assessment or death due to any cause, whichever occurs first, among participants who demonstrated CR or PR as the best overall response per RECIST v1.1. Kaplan-Meier estimate for the median DoR is presented, along with associated 95% confidence interval, estimated using the Brookmeyer-Crowley method. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=14 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=23 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
DoR Per RECIST v1.1 in the PD-L1 CPS ≥20 Population	NA Weeks Interval 18.1 to The median was not reached at the time of data cut off. The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.	NA Weeks Interval 12.1 to The median was not reached at the time of data cut off. The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.

SECONDARY outcome

Timeframe: Up to approximately 43 months

Population: Safety Population: All randomized participants who take at least 1 dose of study intervention. Participants were assigned to the actual study intervention group of feladilimab + pembrolizumab if the participant received any dose of feladilimab. Participants were analyzed according to the actual study intervention received.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study intervention, whether or not considered related to the study intervention. An SAE was defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires in-patient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity, is a congenital anomaly/birth defect, any other situation such as important medical events according to medical or scientific judgement.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Number of Participants With Any Adverse Events (AEs) and Serious Adverse Events (SAEs) Any AE	150 Participants	145 Participants
Number of Participants With Any Adverse Events (AEs) and Serious Adverse Events (SAEs) Any SAE	52 Participants	53 Participants

SECONDARY outcome

Timeframe: Up to approximately 43 months

Population: Safety Population: All randomized participants who take at least 1 dose of study intervention

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study intervention, whether or not considered related to the study intervention. Severity of each AE was reported during the study and was assigned a grade according to the National Cancer Institute- Common Toxicity Criteria for Adverse Events (NCI-CTCAE). AEs severity were graded on a 5-point scale as: 1 = mild; discomfort noticed, but no disruption to daily activity, 2 = moderate; discomfort sufficient to reduce or affect normal daily activity, 3 = severe; inability to work or perform normal daily activity, 4 = life-threatening consequences and 5 = death related to AE.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Number of Participants With AEs by Severity Grade 1	34 Participants	21 Participants
Number of Participants With AEs by Severity Grade 2	48 Participants	54 Participants
Number of Participants With AEs by Severity Grade 3	46 Participants	46 Participants
Number of Participants With AEs by Severity Grade 4	7 Participants	6 Participants
Number of Participants With AEs by Severity Grade 5	15 Participants	18 Participants

SECONDARY outcome

Timeframe: Up to approximately 43 months

Population: Safety Population: All randomized participants who take at least 1 dose of study intervention

An SAE was defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity, is a congenital anomaly/birth defect, any other situation such as important medical events according to medical or scientific judgement. Severity of each SAE was reported during the study and was assigned a grade according to the NCI-CTCAE. SAEs severity were graded on a 5-point scale as: 1 = mild; discomfort noticed, but no disruption to daily activity, 2 = moderate; discomfort sufficient to reduce or affect normal daily activity, 3 = severe; inability to work or perform normal daily activity, 4 = life-threatening consequences and 5 = death related to AE. Data of participants experiencing SAEs of Grade ≥3 have been presented.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Number of Participants With SAEs by Severity	43 Participants	46 Participants

SECONDARY outcome

Timeframe: Up to approximately 43 months

Population: All participants in the safety population were analyzed

AESI were defined as events of potential immunologic etiology, including immune-related AEs (irAEs). Such events recently reported after treatment with other immune modulatory therapy include colitis, uveitis, hepatitis, pneumonitis, diarrhea, endocrine disorders, and specific cutaneous toxicities, as well as other events that may be immune mediated.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Number of Participants With Adverse Events of Special Interest (AESI)	49 Participants	67 Participants

SECONDARY outcome

Timeframe: Up to approximately 43 months

Population: All participants in the safety population were analyzed

AESI were defined as events of potential immunologic etiology, including immune-related AEs (irAEs). Such events recently reported after treatment with other immune modulatory therapy include colitis, uveitis, hepatitis, pneumonitis, diarrhea, endocrine disorders, and specific cutaneous toxicities, as well as other events that may be immune mediated. Severity of each AESI was reported during the study and was assigned a grade according to the NCI-CTCAE. AESIs severity were graded on a 5-point scale as: 1 = mild; discomfort noticed, but no disruption to daily activity, 2 = moderate; discomfort sufficient to reduce or affect normal daily activity, 3 = severe; inability to work or perform normal daily activity, 4 = life-threatening consequences and 5 = death related to AE. Data of participants experiencing AESIs of Grade ≥3 have been presented.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Number of Participants With AESI by Severity	2 Participants	6 Participants

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: All participants in the safety population were analyzed

Number of participants with dose modifications (including dose interruptions, dose delays and treatment discontinuations) were reported by each interventional component.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Number of Participants With Dose Modifications Dose delays by component - pembrolizumab	11 Participants	6 Participants
Number of Participants With Dose Modifications Dose interruption by component - feladilimab	4 Participants	NA Participants Participants in this treatment arm were not dosed with feladilimab
Number of Participants With Dose Modifications Dose interruption by component - placebo	NA Participants Participants in this treatment arm were not dosed with placebo	1 Participants
Number of Participants With Dose Modifications Dose interruption by component - pembrolizumab	0 Participants	1 Participants
Number of Participants With Dose Modifications Dose delays by component - feladilimab	9 Participants	NA Participants Participants in this treatment arm were not dosed with feladilimab
Number of Participants With Dose Modifications Dose delays by component - placebo	NA Participants Participants in this treatment arm were not dosed with placebo	5 Participants
Number of Participants With Dose Modifications Treatment discontinuation by component - feladilimab/placebo	159 Participants	154 Participants
Number of Participants With Dose Modifications Treatment discontinuation by component - pembrolizumab	108 Participants	93 Participants

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

TTD in pain is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the European Organization for Research and Treatment of Cancer Item Library(EORTC IL51) pain domain, i.e. an increase from baseline of at least 8.33 observed at all subsequent non-missing visits. The EORTC Quality of Life Questionnaire 35-Item Head and Neck Module (QLQ-H&N35) is a head and neck specific module with multi-item scales. The questionnaire scores for each scale and single-item measure are averaged and transformed linearly to present a score ranging from 0-100. A high score represents a high/healthy level of functioning. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Time to Deterioration (TTD) in Pain in the PD-L1 CPS ≥1 Population	6.3 Months Interval 5.1 to The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.	10.4 Months Interval 6.3 to The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

TTD in pain is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the EORTC IL51 pain domain, i.e. an increase from baseline of at least 8.33 observed at all subsequent non-missing visits. The EORTC QLQ-H&N35 is a head and neck specific module with multi-item scales. The mouth pain, swallowing, speech problems, opening mouth, coughing, feeding tube, and trouble with social eating domains were administered and referred to as the EORTC IL51. The questionnaire scores for each scale and single-item measure are averaged and transformed linearly to present a score ranging from 0-100. A high score represents a high/healthy level of functioning. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
TTD in Pain in the PD-L1 CPS ≥20 Population	NA Months Interval 5.1 to The median was not reached at the time of data cut off. The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.	12 Months Interval 6.3 to The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: All participants with PD-L1 CPS ≥1 in the mITT population were analyzed.

TTD in physical function is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the PF T-score, i.e. a decrease from baseline of at least 2.4 observed at all subsequent non-missing visits, as measured by the PROMIS PF 8c. The PROMIS PF 8c is an 8-item fixed length short form derived from the PROMIS Physical Function item bank. It includes a 5-point scale with three sets of response options. Scores on the PROMIS PF 8c are reported on a T score metric (mean = 50 and SD = 10), with higher scores reflecting better physical functioning. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=157 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
TTD in Physical Function in the PD-L1 CPS ≥1 Population	4.9 Months Interval 3.5 to 7.7	4.9 Months Interval 3.0 to 6.3

SECONDARY outcome

Timeframe: Up to approximately 16 months

Population: Data for participants with PD-L1 CPS ≥20 in mITT population are presented.

TTD in physical function is defined as the time from randomization to the first definitive meaningful deterioration from baseline in the PF T-score, i.e. a decrease from baseline of at least 2.4 observed at all subsequent non-missing visits, as measured by the PROMIS PF 8c. The PROMIS PF 8c is an 8-item fixed length short form derived from the PROMIS Physical Function item bank. It includes a 5-point scale with three sets of response options. Scores on the PROMIS PF 8c are reported on a T score metric (mean = 50 and SD = 10), with higher scores reflecting better physical functioning. Data are presented for the PD-L1 CPS >=1 participants from mITT population. CPS was defined as the ratio of the combined number of PD-L1 expressing tumor cells and immune cells (lymphocytes and macrophages) to the total number of viable tumor cells.

Outcome measures

Measure	Participants Receiving Feladilimab and Pembrolizumab n=70 Participants Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=69 Participants Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
TTD in Physical Function in the PD-L1 CPS ≥20 Population	4.9 Months Interval 2.1 to The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.	4.9 Months Interval 3.1 to The upper limit of the 95% CI was not calculable from the available data at the time of data cut off.

Adverse Events

Participants Receiving Feladilimab and Pembrolizumab

Serious events: 52 serious events

Other events: 125 other events

Deaths: 116 deaths

Participants Receiving Placebo and Pembrolizumab

Serious events: 53 serious events

Other events: 128 other events

Deaths: 97 deaths

Serious adverse events

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 participants at risk Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 participants at risk Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Blood and lymphatic system disorders Anaemia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Blood and lymphatic system disorders Leukocytosis	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Cardiac disorders Cardio-respiratory arrest	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Colitis	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Constipation	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Diarrhoea	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Dysphagia	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	2.6% 4/156 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Mouth haemorrhage	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Nausea	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Oral cavity fistula	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Oral pain	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Pneumoperitoneum	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Small intestinal perforation	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Stomatitis	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Vomiting	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders Asthenia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders General physical health deterioration	1.9% 3/159 • Number of events 3 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders Pain	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders Pyrexia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders Systemic inflammatory response syndrome	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Hepatobiliary disorders Hepatitis	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Hepatobiliary disorders Hepatotoxicity	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Abscess	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Appendicitis	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Bacteraemia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations COVID-19	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	2.6% 4/156 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations COVID-19 pneumonia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Cellulitis	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Infected skin ulcer	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Localised infection	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Pneumonia	2.5% 4/159 • Number of events 6 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	2.6% 4/156 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Pulmonary sepsis	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Sepsis	1.3% 2/159 • Number of events 3 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Skin infection	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Urinary tract infection	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Wound infection	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Injury, poisoning and procedural complications Ankle fracture	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Injury, poisoning and procedural complications Fracture	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Injury, poisoning and procedural complications Limb injury	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Injury, poisoning and procedural complications Post procedural haemorrhage	0.63% 1/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Injury, poisoning and procedural complications Tracheal haemorrhage	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Injury, poisoning and procedural complications Tracheal obstruction	0.63% 1/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Investigations Blood creatinine increased	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Investigations Hepatic enzyme increased	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Cachexia	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Hypercalcaemia	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.9% 3/156 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Hypoglycaemia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Hypokalaemia	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Hyponatraemia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Malnutrition	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.9% 3/156 • Number of events 3 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Fistula discharge	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Muscular weakness	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Pain in jaw	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Polyarthritis	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Synovitis	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Cancer pain	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Infected neoplasm	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Tumour haemorrhage	2.5% 4/159 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	3.8% 6/156 • Number of events 6 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Epilepsy	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Haemorrhagic stroke	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Neuralgia	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Seizure	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Spinal cord compression	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Syncope	1.9% 3/159 • Number of events 3 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Renal and urinary disorders Acute kidney injury	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Renal and urinary disorders Haematuria	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Acute respiratory failure	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Asphyxia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Aspiration	1.9% 3/159 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Chronic obstructive pulmonary disease	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.3% 2/156 • Number of events 3 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Dyspnoea	2.5% 4/159 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.9% 3/156 • Number of events 3 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Laryngeal haemorrhage	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Lung disorder	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Organising pneumonia	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Pleural effusion	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Pneumonitis	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Respiratory failure	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Stridor	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Vascular disorders Aortic aneurysm	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Vascular disorders Circulatory collapse	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Vascular disorders Distributive shock	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Vascular disorders Embolism	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Vascular disorders Hypertension	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Intervertebral discitis	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Laryngitis	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Lymph gland infection	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Septic shock	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Interstitial lung disease	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Laryngeal obstruction	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Pharyngeal stenosis	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Gastric ulcer	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Pancreatitis acute	0.63% 1/159 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Large intestinal obstruction	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Hypopharyngeal cancer	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Headache	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Injury, poisoning and procedural complications Femoral neck fracture	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Back pain	1.3% 2/159 • Number of events 2 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.00% 0/156 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Vascular disorders Shock haemorrhagic	0.00% 0/159 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	0.64% 1/156 • Number of events 1 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations Pneumonia aspiration	2.5% 4/159 • Number of events 5 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	2.6% 4/156 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.

Other adverse events

Measure	Participants Receiving Feladilimab and Pembrolizumab n=159 participants at risk Participants were administered feladilimab (GSK3359609-humanized anti-ICOS IgG4 mAb) and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.	Participants Receiving Placebo and Pembrolizumab n=156 participants at risk Participants were administered placebo and pembrolizumab (humanized anti-PD-1 IgG4 mAb) as an IV infusion Q3W.
Blood and lymphatic system disorders Anaemia	16.4% 26/159 • Number of events 42 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	13.5% 21/156 • Number of events 26 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Endocrine disorders Hypothyroidism	12.6% 20/159 • Number of events 20 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	10.3% 16/156 • Number of events 16 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Constipation	13.8% 22/159 • Number of events 28 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	15.4% 24/156 • Number of events 26 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Diarrhoea	13.2% 21/159 • Number of events 25 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	8.3% 13/156 • Number of events 19 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Dysphagia	10.7% 17/159 • Number of events 17 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	9.6% 15/156 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Nausea	10.7% 17/159 • Number of events 21 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	10.9% 17/156 • Number of events 20 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Vomiting	7.5% 12/159 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	5.1% 8/156 • Number of events 8 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders Asthenia	10.7% 17/159 • Number of events 17 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	9.0% 14/156 • Number of events 23 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders Fatigue	18.2% 29/159 • Number of events 30 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	18.6% 29/156 • Number of events 32 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
General disorders Pyrexia	6.9% 11/159 • Number of events 13 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	7.1% 11/156 • Number of events 12 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Investigations Alanine aminotransferase increased	5.7% 9/159 • Number of events 10 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	7.7% 12/156 • Number of events 16 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Investigations Aspartate aminotransferase increased	7.5% 12/159 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	7.1% 11/156 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Investigations Blood alkaline phosphatase increased	5.0% 8/159 • Number of events 9 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	2.6% 4/156 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Investigations Weight decreased	12.6% 20/159 • Number of events 20 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	17.3% 27/156 • Number of events 29 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Decreased appetite	9.4% 15/159 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	17.9% 28/156 • Number of events 28 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Hypercalcaemia	6.9% 11/159 • Number of events 14 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	5.1% 8/156 • Number of events 10 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Hypokalaemia	6.9% 11/159 • Number of events 17 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	4.5% 7/156 • Number of events 10 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Metabolism and nutrition disorders Hyponatraemia	8.2% 13/159 • Number of events 25 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	4.5% 7/156 • Number of events 7 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Arthralgia	8.2% 13/159 • Number of events 16 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	7.1% 11/156 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Back pain	5.0% 8/159 • Number of events 8 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	6.4% 10/156 • Number of events 10 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Musculoskeletal and connective tissue disorders Neck pain	5.0% 8/159 • Number of events 8 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	7.7% 12/156 • Number of events 12 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Nervous system disorders Headache	9.4% 15/159 • Number of events 19 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	9.0% 14/156 • Number of events 17 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Psychiatric disorders Insomnia	9.4% 15/159 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	3.2% 5/156 • Number of events 5 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Cough	6.9% 11/159 • Number of events 14 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	7.1% 11/156 • Number of events 11 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Dyspnoea	10.7% 17/159 • Number of events 19 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	12.2% 19/156 • Number of events 19 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Skin and subcutaneous tissue disorders Pruritus	6.9% 11/159 • Number of events 15 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	10.9% 17/156 • Number of events 19 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Skin and subcutaneous tissue disorders Rash	5.7% 9/159 • Number of events 12 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	13.5% 21/156 • Number of events 32 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Gastrointestinal disorders Abdominal pain	3.1% 5/159 • Number of events 6 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	5.8% 9/156 • Number of events 11 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Respiratory, thoracic and mediastinal disorders Productive cough	2.5% 4/159 • Number of events 4 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	5.1% 8/156 • Number of events 9 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Psychiatric disorders Anxiety	5.0% 8/159 • Number of events 8 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	1.9% 3/156 • Number of events 3 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.
Infections and infestations COVID-19	3.1% 5/159 • Number of events 5 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.	5.8% 9/156 • Number of events 9 • All cause mortality, non-SAEs and SAEs were collected from Day 1 to up to approximately 43 months. 2 participants were initially randomized to placebo+pembrolizumab arm but were dosed with feladilimab. Therefore, they were included in feladilimab+pembrolizumab arm of the safety population. The 2 participants enrolled but excluded from the mITT population (1 from each arm) were both included in placebo+pembrolizumab arm for the safety population, as both were only dosed with pembrolizumab.

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