Trial Outcomes & Findings for Safety and Efficacy of Pembrolizumab Compared to Placebo in Resected High-risk Stage II Melanoma (MK-3475-716/KEYNOTE-716) (NCT NCT03553836)

Last Updated: 2024-11-29

Results Overview

RFS was defined as the time from randomization to any of the following events: recurrence of melanoma at any site (local, in-transit or regional lymph nodes or distant recurrence) per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) or death due to any cause, whichever occurs first. Per protocol, final analysis for this primary outcome measure was performed using the initial pembrolizumab or placebo treatment with a protocol-specified analysis data cut-off date of June-21-2021.

Recruitment status

ACTIVE_NOT_RECRUITING

Study phase

PHASE3

Target enrollment

976 participants

Primary outcome timeframe

Up to ~32.7 months

Results posted on

2024-11-29

Participant Flow

Per protocol, response/progression or adverse events (AEs) during re-challenge/switch-over in Part 2 were not counted towards the recurrence-free survival (RFS) outcome measure or safety outcome measures respectively.

Participant milestones

Participant milestones
Measure	Pembrolizumab Participants received 200 mg pembrolizumab (2 mg/kg for a maximum of 200 mg in pediatric participants) by intravenous (IV) infusion once every 3 weeks (Q3W; 21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of pembrolizumab and experienced disease recurrence may have been eligible for re-challenge with pembrolizumab at the same dose and schedule of 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.	Placebo Participants received saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of placebo and experienced disease recurrence may have been eligible to switch over to pembrolizumab 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.
Overall Study STARTED	487	489
Overall Study Treated	483	486
Overall Study Re-challenged or Switched-over to Pembrolizumab	1	45
Overall Study COMPLETED	0	0
Overall Study NOT COMPLETED	487	489

Reasons for withdrawal

Reasons for withdrawal
Measure	Pembrolizumab Participants received 200 mg pembrolizumab (2 mg/kg for a maximum of 200 mg in pediatric participants) by intravenous (IV) infusion once every 3 weeks (Q3W; 21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of pembrolizumab and experienced disease recurrence may have been eligible for re-challenge with pembrolizumab at the same dose and schedule of 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.	Placebo Participants received saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of placebo and experienced disease recurrence may have been eligible to switch over to pembrolizumab 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.
Overall Study Ongoing in Study	460	459
Overall Study Withdrawal by Subject	9	10
Overall Study Lost to Follow-up	1	3
Overall Study Death	17	17

Baseline Characteristics

Safety and Efficacy of Pembrolizumab Compared to Placebo in Resected High-risk Stage II Melanoma (MK-3475-716/KEYNOTE-716)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Pembrolizumab n=487 Participants Participants received 200 mg pembrolizumab (2 mg/kg for a maximum of 200 mg in pediatric participants) by intravenous (IV) infusion once every 3 weeks (Q3W; 21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of pembrolizumab and experienced disease recurrence may have been eligible for re-challenge with pembrolizumab at the same dose and schedule of 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.	Placebo n=489 Participants Participants received saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of placebo and experienced disease recurrence may have been eligible to switch over to pembrolizumab 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.	Total n=976 Participants Total of all reporting groups
Age, Continuous	59.0 Years STANDARD_DEVIATION 12.6 • n=5 Participants	59.6 Years STANDARD_DEVIATION 13.3 • n=7 Participants	59.3 Years STANDARD_DEVIATION 12.9 • n=5 Participants
Sex: Female, Male Female	187 Participants n=5 Participants	200 Participants n=7 Participants	387 Participants n=5 Participants
Sex: Female, Male Male	300 Participants n=5 Participants	289 Participants n=7 Participants	589 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	49 Participants n=5 Participants	30 Participants n=7 Participants	79 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	390 Participants n=5 Participants	409 Participants n=7 Participants	799 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	48 Participants n=5 Participants	50 Participants n=7 Participants	98 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Asian	4 Participants n=5 Participants	1 Participants n=7 Participants	5 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	4 Participants n=5 Participants	4 Participants n=7 Participants	8 Participants n=5 Participants
Race (NIH/OMB) White	435 Participants n=5 Participants	439 Participants n=7 Participants	874 Participants n=5 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	42 Participants n=5 Participants	45 Participants n=7 Participants	87 Participants n=5 Participants
Melanoma Primary Tumor (T) Stage T3a	2 Participants n=5 Participants	0 Participants n=7 Participants	2 Participants n=5 Participants
Melanoma Primary Tumor (T) Stage T3b	200 Participants n=5 Participants	201 Participants n=7 Participants	401 Participants n=5 Participants
Melanoma Primary Tumor (T) Stage T4a	113 Participants n=5 Participants	116 Participants n=7 Participants	229 Participants n=5 Participants
Melanoma Primary Tumor (T) Stage T4b	172 Participants n=5 Participants	172 Participants n=7 Participants	344 Participants n=5 Participants

PRIMARY outcome

Timeframe: Up to ~32.7 months

Population: All randomized participants.

Outcome measures

Outcome measures
Measure	Pembrolizumab n=487 Participants Participants received 200 mg pembrolizumab (2 mg/kg for a maximum of 200 mg in pediatric participants) by intravenous (IV) infusion once every 3 weeks (Q3W; 21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1.	Placebo n=489 Participants Participants received saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1.
Recurrence-free Survival (RFS)	NA Months Median, Upper limit and lower limit not reached at the time of data cut-off due to insufficient number of participants with recurrence.	NA Months Interval 29.9 to Median and Upper limit not reached at the time of data cut-off due to insufficient number of participants with recurrence.

SECONDARY outcome

Timeframe: Up to ~9 years

DMFS will be defined as the time from randomization to the first diagnosis of a distant metastasis per RECIST 1.1. Distant metastasis will refer to cancer that has spread from the original (primary) tumor and beyond local tissues and lymph nodes to distant organs or distant lymph nodes. DMFS will be reported for randomized participants.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to ~15 years

OS will be defined as the time from randomization to death due to any cause. OS will be reported for randomized participants.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: Up to ~19.3 months

Population: All randomized participants who received at least one dose of study treatment.

An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. Per protocol, analysis for this outcome measure was performed using the initial pembrolizumab or placebo treatment.

Outcome measures

Outcome measures
Measure	Pembrolizumab n=483 Participants Participants received 200 mg pembrolizumab (2 mg/kg for a maximum of 200 mg in pediatric participants) by intravenous (IV) infusion once every 3 weeks (Q3W; 21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1.	Placebo n=486 Participants Participants received saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1.
Number of Participants Who Experienced at Least One Adverse Event (AE)	461 Participants	444 Participants

SECONDARY outcome

Timeframe: Up to ~19.3 months

Population: All randomized participants who received at least one dose of study treatment.

Outcome measures

Outcome measures
Measure	Pembrolizumab n=483 Participants Participants received 200 mg pembrolizumab (2 mg/kg for a maximum of 200 mg in pediatric participants) by intravenous (IV) infusion once every 3 weeks (Q3W; 21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1.	Placebo n=486 Participants Participants received saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1.
Number of Participants Who Discontinued Study Treatment Due to an AE	84 Participants	22 Participants

Adverse Events

Pembrolizumab

Serious events: 101 serious events

Other events: 417 other events

Deaths: 17 deaths

Placebo

Serious events: 91 serious events

Other events: 364 other events

Deaths: 18 deaths

Placebo Switched Over to Pembrolizumab

Serious events: 6 serious events

Other events: 26 other events

Deaths: 3 deaths

Serious adverse events

Other adverse events

Additional Information

Senior Vice President, Global Clinical Development

Merck Sharp & Dohme LLC.

Phone: 1-800-672-6372

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee If publication activity is not directed by the Sponsor, the investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission. This allows the Sponsor to protect proprietary information and to provide comments.
Publication restrictions are in place

Restriction type: OTHER

Serious adverse events
Measure	Pembrolizumab n=483 participants at risk Participants received 200 mg pembrolizumab (2 mg/kg for a maximum of 200 mg in pediatric participants) by intravenous (IV) infusion once every 3 weeks (Q3W; 21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of pembrolizumab and experienced disease recurrence may have been eligible for re-challenge with pembrolizumab at the same dose and schedule of 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.	Placebo n=486 participants at risk Participants received saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1. Participants who completed the initial treatment of 17 cycles of placebo and experienced disease recurrence may have been eligible to switch over to pembrolizumab 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.	Placebo Switched Over to Pembrolizumab n=45 participants at risk Participants who received the initial treatment of saline placebo by IV infusion Q3W (21-day cycles) for up to 17 cycles (up to \~1 year) in Part 1 and experienced disease recurrence may have been eligible to switch over to pembrolizumab 200 mg Q3W (21-day cycles) for up to 35 cycles (up to \~2 years) in Part 2.
Blood and lymphatic system disorders Lymphadenopathy	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Cardiac disorders Acute myocardial infarction	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.41% 2/486 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Cardiac disorders Atrial fibrillation	0.83% 4/483 • Number of events 5 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Cardiac disorders Autoimmune myocarditis	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Cardiac disorders Cardiac failure	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Cardiac disorders Cardiomyopathy	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Cardiac disorders Coronary artery disease	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.41% 2/486 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Cardiac disorders Mitral valve incompetence	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Ear and labyrinth disorders Vertigo	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Endocrine disorders Adrenal insufficiency	0.83% 4/483 • Number of events 4 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Endocrine disorders Endocrine disorder	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Endocrine disorders Hypophysitis	0.41% 2/483 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Endocrine disorders Hypopituitarism	0.41% 2/483 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Eye disorders Glaucoma	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Eye disorders Macular detachment	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Anal fistula	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Autoimmune colitis	0.41% 2/483 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Colitis	0.83% 4/483 • Number of events 4 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Diarrhoea	0.41% 2/483 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Haematemesis	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Immune-mediated enterocolitis	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Inguinal hernia	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Gastrointestinal disorders Pancreatitis	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
General disorders Chest pain	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
General disorders Cyst	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
General disorders Infusion site urticaria	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
General disorders Pyrexia	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Hepatobiliary disorders Autoimmune hepatitis	0.62% 3/483 • Number of events 3 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Hepatobiliary disorders Hepatotoxicity	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	2.2% 1/45 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Immune system disorders Sarcoidosis	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Abdominal wall abscess	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Abscess soft tissue	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Anorectal infection	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Appendicitis	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	2.2% 1/45 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations COVID-19 pneumonia	0.41% 2/483 • Number of events 2 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.62% 3/486 • Number of events 3 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Cellulitis	0.62% 3/483 • Number of events 3 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Cellulitis streptococcal	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Cystitis	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Enterocolitis infectious	0.21% 1/483 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/486 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.
Infections and infestations Infected seroma	0.00% 0/483 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.21% 1/486 • Number of events 1 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.	0.00% 0/45 • All-cause mortality (ACM) : Up to ~32.7 months and safety: Up to ~30.2 months ACM was analyzed in all randomized participants. Safety was analyzed in all participants who received ≥1 dose of study drug. Per protocol disease progression of cancer was not considered an AE unless related to study drug. Thus MedDRA preferred terms "Neoplasm progression", "Malignant neoplasm progression", "Disease progression" unrelated to study drug are excluded as AEs. ACM and Safety were analyzed separately in participants who switched over from placebo to pembrolizumab.