Trial Outcomes & Findings for Letetresgene Autoleucel Engineered T Cells in NY-ESO-1 Positive Participants With Advanced Myxoid/ Round Cell Liposarcoma (NCT NCT02992743)

Last Updated: 2023-04-11

Results Overview

Overall response rate (ORR) defined as the percentage of participants with a confirmed complete response (CR) or confirmed partial response (PR) via investigator assessment per RECIST (Response Evaluation Criteria In Solid Tumors Criteria) v1.1 relative to the total number of participants in the analysis population. Partial response is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. Complete response is defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (\<)10 millimeters (mm). Confidence intervals (CI) were calculated using the exact (Clopper-Pearson) method.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

23 participants

Primary outcome timeframe

Up to 24 months

Results posted on

2023-04-11

Participant Flow

This was an open-label study evaluating the safety and tolerability of autologous T-Cells expressing enhanced T-cell receptors (TCRs) specific for New York esophageal squamous cell carcinoma (NY-ESO)-1 (letetresgene autoleucel, lete-cel, GSK3377794) in Human Leukocyte Antigen (HLA)-A\*02:01, HLA-A\*02:05 and/or HLA-A\*02:06 participants with Advanced Myxoid/ Round Cell Liposarcoma.

A total of 23 participants were enrolled in this study. Out of 23 participants, 20 participants received NY-ESO-1c259 T cell infusion.

Participant milestones

Participant milestones
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 milligrams per meter square per day (mg/m\^2/day) plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Overall Study STARTED	13	10
Overall Study Received T-cell Infusion	10	10
Overall Study COMPLETED	9	8
Overall Study NOT COMPLETED	4	2

Reasons for withdrawal

Reasons for withdrawal
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 milligrams per meter square per day (mg/m\^2/day) plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Overall Study Withdrawal by Subject	1	1
Overall Study Death-Prior to T-Cell Infusion	1	0
Overall Study Did Not Meet Inclusion/Exclusion	1	0
Overall Study No measurable disease	1	0
Overall Study Lost to Follow-up	0	1

Baseline Characteristics

Letetresgene Autoleucel Engineered T Cells in NY-ESO-1 Positive Participants With Advanced Myxoid/ Round Cell Liposarcoma

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=13 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Total n=23 Participants Total of all reporting groups
Age, Continuous	50.0 YEARS STANDARD_DEVIATION 6.79 • n=5 Participants	46.0 YEARS STANDARD_DEVIATION 11.61 • n=7 Participants	48.3 YEARS STANDARD_DEVIATION 9.19 • n=5 Participants
Sex: Female, Male Female	6 Participants n=5 Participants	3 Participants n=7 Participants	9 Participants n=5 Participants
Sex: Female, Male Male	7 Participants n=5 Participants	7 Participants n=7 Participants	14 Participants n=5 Participants
Race/Ethnicity, Customized Black or African American	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized Other: More than one race	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized White	11 Participants n=5 Participants	10 Participants n=7 Participants	21 Participants n=5 Participants

PRIMARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population, which included all participants who underwent leukapheresis and received GSK3377794.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Overall Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Investigator Assessment	20 Percentage of participants Interval 2.5 to 55.6	40 Percentage of participants Interval 12.2 to 73.8

PRIMARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population, which included all participants who underwent leukapheresis and received GSK3377794.

The Best Overall Response (BOR) with confirmation for a participant is defined as the best confirmed response (Confirmed Complete Response \[CR\] \> Confirmed Partial Response \[PR\] \> Stable Disease \[SD\] \> Progressive Disease \[PD\] \> Not Evaluable \[NE\]) from first T cell infusion until disease progression or initiation of new anti-cancer therapy, whichever is earlier, as assessed by the investigator per RECIST v1.1 Criteria.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Investigator Assessment Complete Response (CR)	0 Participants	0 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Investigator Assessment Partial Response (PR)	2 Participants	4 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Investigator Assessment Stable Disease (SD)	8 Participants	5 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Investigator Assessment Progressive Disease (PD)	0 Participants	1 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Investigator Assessment Not Evaluable (NE)	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794. Only responders by investigator assessment were included in this analysis.

Time to response was defined as the interval of time between the date of T-cell infusion and the first documented evidence of the confirmed response (PR or CR), in the subset of participants with a confirmed PR or CR as their best confirmed overall response. Partial response is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. Complete response is defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (\<)10 mm.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=2 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=4 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Time to Response (TTR) Assessed by Investigator	1.856 Months Interval 0.92 to 2.793	1.938 Months Interval 1.889 to 2.366

SECONDARY outcome

Timeframe: Up to 24 months

Duration of response was defined as the interval between the initial date of confirmed response (PR/CR) and the date of progressive disease or death among participants with a confirmed response per RECIST 1.1. Partial response is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. Complete response is defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (\<)10 millimeters. Kaplan-Meier Median and 95% confidence intervals are presented. Confidence intervals were calculated using the Brookmeyer-Crowley method.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=2 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=4 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Duration of Response (DOR) Assessed by Investigator	5.31 Months Interval 1.87 to 8.74	7.47 Months Interval 6.01 to Statistics that cannot be calculated due to insufficient events are presented as "NA"

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794.

Progression free survival was defined as the interval between the date of T cell infusion and the earliest date of disease progression or death due to any cause. Progressive disease (PD) is defined as at least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study. PFS based on responses assessed by investigator per RECIST v1.1 is presented. Kaplan-Meier Median and 95% confidence intervals are presented. Confidence intervals were calculated using the Brookmeyer-Crowley method.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Progression Free Survival (PFS) Assessed by Investigator	5.36 Months Interval 2.0 to 11.5	8.74 Months Interval 0.89 to Statistics that cannot be calculated due to insufficient events are presented as "NA"

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population, which included all participants who underwent leukapheresis and received GSK3377794.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Independent Reviewer Assessment Complete Response (CR)	0 Participants	0 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Independent Reviewer Assessment Partial Response (PR)	2 Participants	4 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Independent Reviewer Assessment Stable Disease (SD)	8 Participants	3 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Independent Reviewer Assessment Progressive Disease (PD)	0 Participants	0 Participants
Best Overall Response (BOR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Independent Reviewer Assessment Not Evaluable (NE)	0 Participants	3 Participants

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population, which included all participants who underwent leukapheresis and received GSK3377794.

Overall response rate (ORR) defined as the percentage of participants with a confirmed complete response (CR) or confirmed partial response (PR) via independent reviewer assessment per RECIST v1.1 relative to the total number of participants in the analysis population. Partial response is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. Complete response is defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (\<)10 millimeters (mm). Confidence intervals (CI) were calculated using the exact (Clopper-Pearson) method.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Overall Response Rate (ORR) Per Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 by Independent Reviewer	20 Percentage of participants Interval 2.5 to 55.6	40 Percentage of participants Interval 12.2 to 73.8

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794. Only responders by independent reviewer were included in this analysis.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=2 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=4 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Time to Response (TTR) Assessed by Independent Reviewer	2.366 Months Interval 1.84 to 2.891	1.889 Months Interval 1.413 to 1.938

SECONDARY outcome

Timeframe: Up to 24 months

Duration of response was defined as the interval between the initial date of confirmed response (PR/CR) and the date of progressive disease or death among participants with a confirmed response per RECIST 1.1. Partial response is defined as at least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. Complete response is defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (\<)10 mm. Kaplan-Meier Median and 95% confidence intervals are presented. Confidence intervals were calculated using the Brookmeyer-Crowley method.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=2 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=4 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Duration of Response (DOR) Assessed by Independent Reviewer	NA Months Statistics that cannot be calculated due to insufficient events are presented as "NA"	7.16 Months Interval 4.57 to Statistics that cannot be calculated due to insufficient events are presented as "NA"

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794.

Progression free survival was defined as the interval between the date of T cell infusion and the earliest date of disease progression or death due to any cause. Progressive disease (PD) is defined as at least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study. PFS based on responses assessed by independent reviewer per RECIST v1.1 is presented. Kaplan-Meier Median and 95% confidence intervals are presented. Confidence intervals were calculated using the Brookmeyer-Crowley method.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Progression Free Survival (PFS) Assessed by Independent Reviewer	4.67 Months Interval 2.79 to Statistics that cannot be calculated due to insufficient events are presented as "NA"	9.03 Months Interval 5.32 to Statistics that cannot be calculated due to insufficient events are presented as "NA"

SECONDARY outcome

Timeframe: Up to 24 months

Population: Intent-to-Treat (ITT) Population, which included all participants who underwent leukapheresis.

An AE is 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. SAE is defined as any untoward medical occurrence that, at any dose can result in death, is life threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity, is a congenital anomaly/birth or is medically significant or requires intervention to prevent one or the outcomes listed above.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=13 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Number of Participants With Serious Adverse Events (SAEs) and Non-SAEs Non-SAEs	13 Participants	10 Participants
Number of Participants With Serious Adverse Events (SAEs) and Non-SAEs SAEs	5 Participants	7 Participants

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794.

An AESI may be of scientific and medical concern related to the treatment, monitored, and rapidly communicated by investigator to sponsor. The AESI included events of Cytokine release syndrome (CRS), Haematopoietic cytopenias (including pancytopenia and aplastic anaemia), Graft versus host disease (GvHD), Immune Effector-Cell Associated Neurotoxicity Syndrome (ICANS), and Guillain-Barre syndrome.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Number of Participants With Adverse Event of Special Interest (AESI) Participants with any AESI	10 Participants	10 Participants
Number of Participants With Adverse Event of Special Interest (AESI) Cytokine release syndrome	6 Participants	10 Participants
Number of Participants With Adverse Event of Special Interest (AESI) Haematopoietic cytopenias (including pancytopenia and aplastic anaemia)	10 Participants	10 Participants

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794.

Blood samples were collected for the analysis of following hematology parameters: hemoglobin, lymphocytes, neutrophils, platelets, leukocytes. Laboratory parameters were graded according to National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 4.0, where Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. Baseline is the most recent, non-missing value from a central laboratory within 7 days prior to the lymphodepleting chemotherapy. An increase in grade is defined as an increase in CTCAE grade relative to baseline grade. Data of number of participants with any grade increase at worst-case post-baseline (maximum grade increase post-baseline) is presented.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Number of Participants With Any Grade Increase in Hematology Results at Worst-case Post-baseline Hemoglobin Anemia	9 Participants	10 Participants
Number of Participants With Any Grade Increase in Hematology Results at Worst-case Post-baseline Lymphocyte count decreased	10 Participants	10 Participants
Number of Participants With Any Grade Increase in Hematology Results at Worst-case Post-baseline Neutrophils	10 Participants	10 Participants
Number of Participants With Any Grade Increase in Hematology Results at Worst-case Post-baseline Platelets	9 Participants	10 Participants
Number of Participants With Any Grade Increase in Hematology Results at Worst-case Post-baseline Leukocytes	10 Participants	10 Participants

SECONDARY outcome

Timeframe: Up to 24 months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794.

Blood samples were collected for the analysis clinical chemistry parameters: glucose, albumin, alkaline phosphatase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, creatinine, potassium, magnesium, sodium, phosphate, calcium. Laboratory parameters were graded according to National Cancer Institute-Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 4.0, where Grade1: mild; Grade 2: moderate; Grade 3: severe or medically significant; Grade 4: life-threatening consequences. Baseline is the most recent, non-missing value from a central laboratory within 7 days prior to the lymphodepleting chemotherapy. An increase in grade is defined as an increase in CTCAE grade relative to baseline grade. Data of number of participants with any grade increase at worst-case post-baseline (maximum grade increase post-baseline) is presented.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Potassium Hypokalemia	5 Participants	9 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Magnesium Hypermagnesemia	5 Participants	2 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Glucose Hyperglycemia	5 Participants	8 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Glucose Hypoglycemia	1 Participants	4 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Albumin	9 Participants	9 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Alkaline Phosphatase	4 Participants	6 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline ALT	7 Participants	7 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline AST	8 Participants	8 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Bilirubin	3 Participants	2 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Creatinine	4 Participants	2 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Potassium Hyperkalemia	1 Participants	1 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Magnesium Hypomagnesemia	2 Participants	6 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Phosphate	9 Participants	10 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Sodium Hypernatremia	2 Participants	1 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Sodium Hyponatremia	8 Participants	9 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Calcium Corrected for Albumin Hypercalcemia	2 Participants	1 Participants
Number of Participants With Any Grade Increase in Clinical Chemistry Results at Worst-case Post-baseline Calcium Corrected for Albumin Hypocalcemia	1 Participants	7 Participants

SECONDARY outcome

Timeframe: Day 1 (pre-infusion), and at Week 12, Week 24, and 1 year post-infusion

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794.. Only those participants with RCL assessed post T-cell infusion were included in the analysis.

RCL was monitored using a polymerase chain reaction (PCR)-based assay that detects and measures copies of the gene coding for the vector's envelope protein, namely vesicular stomatitis virus G protein (VSV-G).

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=8 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Number of Participants With Replication Competent Lentivirus (RCL)	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Up to 2 years

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794. Number of participants analyzed comprises participants for whom integration site analysis was conducted.

Peripheral blood mononuclear cells (PBMC) samples were collected for monitoring insertional oncogenesis by PCR for gene modified cells in the blood. DNA from participant identified with \>1% PBMC at \>=1 year post T-cell infusion was sent for integration site analysis. Integration site analysis was used to assess the possibility of insertional oncogenesis. Participants with insertional oncogenesis were participants with any clones representing \>20% of the total.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=1 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=2 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Number of Participants With Insertional Oncogenesis	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Up to 24 Months

Population: Modified Intent-to-Treat (mITT) population which included all participants who underwent leukapheresis and received GSK3377794. Only those participants with post-baseline ADA results were analyzed.

Serum samples were collected to analyze for the presence of ADAs using validated immunoassays.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=7 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Number of Participants With Positive Anti-drug Antibodies (ADAs)	0 Participants	0 Participants

SECONDARY outcome

Timeframe: Day 2 to Day 15

Cmax was defined as peak cell expansion during the interventional phase. Blood samples were collected to measure Cmax.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Maximum Transgene Expansion (Cmax) of GSK3377794	66991.71 Copies per microgram genomic DNA Geometric Coefficient of Variation 127.0	108485.91 Copies per microgram genomic DNA Geometric Coefficient of Variation 53.4

SECONDARY outcome

Timeframe: Day 2 to Day 15

Tmax was defined as time to peak cell expansion during the interventional phase. Blood samples were collected to measure Tmax.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Time to Cmax (Tmax)	2 Days Interval 2.0 to 13.0	4 Days Interval 2.0 to 15.0

SECONDARY outcome

Timeframe: Up to 28 days

Area under the cell expansion-time curve from first T-cell infusion to Day 28. Blood samples were collected to measure AUC (0-28 days).

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=9 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=9 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Area Under the Time Curve From Zero to Time 28 Days AUC(0-28) of GSK3377794	727135.6 Days*copies per microgram genomic DNA Geometric Coefficient of Variation 223.9	1142798.27 Days*copies per microgram genomic DNA Geometric Coefficient of Variation 70.7

SECONDARY outcome

Timeframe: Baseline, Day 1, Day 4 and Day 8

Population: Modified Intent-to-Treat (mITT) population. Only those participants with data available at the specified data points were analyzed.

Triplicate 12-Lead ECGs were collected at baseline visit and single ECGs at other timepoints. At each time point during the study ECG was taken using an ECG machine that automatically calculates the heart rate and measured the PR interval, QRS duration, QTcB, QTcF intervals, RR interval and uncorrected QT interval. Baseline is the most recent, non-missing value within 7 days prior to the lymphodepleting chemotherapy. Change from baseline was to be calculated by subtracting post-dose value from baseline value.

Outcome measures

SECONDARY outcome

Timeframe: Baseline, Day 1 (Pre-dose), Day 4 and Day 8

Single 12-lead ECG was to be obtained at designated time points during the study using an ECG machine that automatically calculates the heart rate and measures PR, QRS, QT, and QTc intervals. Baseline is the most recent, non-missing value within 7 days prior to the lymphodepleting chemotherapy. Change from baseline was to be calculated by subtracting post-dose value from baseline value.

Outcome measures

Outcome measures
Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Change From Baseline in ECG Mean Heart Rate BASELINE	73.0 Beats per minute (beats/minute) Standard Deviation 12.34	78.0 Beats per minute (beats/minute) Standard Deviation 20.06
Change From Baseline in ECG Mean Heart Rate DAY 1	1.6 Beats per minute (beats/minute) Standard Deviation 10.08	4.8 Beats per minute (beats/minute) Standard Deviation 14.20
Change From Baseline in ECG Mean Heart Rate DAY 4	20.1 Beats per minute (beats/minute) Standard Deviation 16.34	38.9 Beats per minute (beats/minute) Standard Deviation 21.95
Change From Baseline in ECG Mean Heart Rate DAY 8	5.4 Beats per minute (beats/minute) Standard Deviation 12.72	9.1 Beats per minute (beats/minute) Standard Deviation 16.37

Adverse Events

Reduced Lymphodepletion Dose Plus GSK3377794

Serious events: 5 serious events

Other events: 13 other events

Deaths: 5 deaths

Standard Lymphodepletion Dose Plus GSK3377794

Serious events: 7 serious events

Other events: 10 other events

Deaths: 0 deaths

Serious adverse events

Other adverse events

Additional Information

GSK Response Center

GlaxoSmithKline

Phone: 866-435-7343

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee GSK agreements may vary with individual investigators, but will not prohibit any investigator from publishing. GSK supports the publication of results from all centers of a multi-center trial but requests that reports based on single site data not precede the primary publication of the entire clinical trial.
Publication restrictions are in place

Restriction type: OTHER

Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 Participants Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval PR Interval, DAY 8	-8.1 Milliseconds (msec) Standard Deviation 14.9	1 Milliseconds (msec) Standard Deviation 9.32
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval PR Interval, BASELINE	152.9 Milliseconds (msec) Standard Deviation 14.59	142 Milliseconds (msec) Standard Deviation 12.72
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval PR Interval, DAY 1	-2.3 Milliseconds (msec) Standard Deviation 8.66	-2.2 Milliseconds (msec) Standard Deviation 9.82
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval PR Interval, DAY 4	-10.7 Milliseconds (msec) Standard Deviation 17.18	-4 Milliseconds (msec) Standard Deviation 12.96
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QRS Duration, BASELINE	91.2 Milliseconds (msec) Standard Deviation 16.53	86.1 Milliseconds (msec) Standard Deviation 15.01
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QRS Duration, DAY 1	2.8 Milliseconds (msec) Standard Deviation 18.87	0.9 Milliseconds (msec) Standard Deviation 6.49
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QRS Duration, DAY 4	2.3 Milliseconds (msec) Standard Deviation 20.43	0.8 Milliseconds (msec) Standard Deviation 5.75
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QRS Duration, DAY 8	-2.7 Milliseconds (msec) Standard Deviation 25.75	-1 Milliseconds (msec) Standard Deviation 5.86
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QT Interval, BASELINE	401.1 Milliseconds (msec) Standard Deviation 11.71	389.3 Milliseconds (msec) Standard Deviation 33.57
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QT Interval, DAY 1	-6.4 Milliseconds (msec) Standard Deviation 23.51	-8.1 Milliseconds (msec) Standard Deviation 33.74
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QT Interval, DAY 4	-49.4 Milliseconds (msec) Standard Deviation 38.59	-72.5 Milliseconds (msec) Standard Deviation 47.65
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QT Interval, DAY 8	-16.7 Milliseconds (msec) Standard Deviation 21.63	-4.4 Milliseconds (msec) Standard Deviation 43.41
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcB Interval, BASELINE	427 Milliseconds (msec) Standard Deviation 4.24	423.3 Milliseconds (msec) Standard Deviation 19.35
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcB Interval, DAY 1	28 Milliseconds (msec) Standard Deviation NA Number of Participants analyzed was 1 only.	36.3 Milliseconds (msec) Standard Deviation 34.03
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcB Interval, DAY 4	10 Milliseconds (msec) Standard Deviation 24.04	8 Milliseconds (msec) Standard Deviation 25.46
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcB Interval, DAY 8	1 Milliseconds (msec) Standard Deviation NA Number of Participants analyzed was 1 only.	47 Milliseconds (msec) Standard Deviation 50.27
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcF Interval, BASELINE	429.9 Milliseconds (msec) Standard Deviation 23.75	425.3 Milliseconds (msec) Standard Deviation 16.18
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcF Interval, DAY 1	-10.1 Milliseconds (msec) Standard Deviation 21.06	1.3 Milliseconds (msec) Standard Deviation 17.36
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcF Interval, DAY 4	-25.3 Milliseconds (msec) Standard Deviation 36.62	3.3 Milliseconds (msec) Standard Deviation 31.1
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval QTcF Interval, DAY 8	-7.5 Milliseconds (msec) Standard Deviation 22.63	16.2 Milliseconds (msec) Standard Deviation 39.96
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval RR Interval, BASELINE	842.6 Milliseconds (msec) Standard Deviation 144.62	807.6 Milliseconds (msec) Standard Deviation 166.39
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval RR Interval, DAY 1	-15.8 Milliseconds (msec) Standard Deviation 98.77	5.3 Milliseconds (msec) Standard Deviation 43.1
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval RR Interval, DAY 4	-162.5 Milliseconds (msec) Standard Deviation 179.21	-188 Milliseconds (msec) Standard Deviation 11.31
Change From Baseline in Electrocardiogram (ECG) Parameters- PR Interval, QRS Duration, QT Interval, QTcB Interval, QTcF Interval and RR Interval RR Interval, DAY 8	-71.6 Milliseconds (msec) Standard Deviation 109.66	-138.5 Milliseconds (msec) Standard Deviation 77.72

Measure	Reduced Lymphodepletion Dose Plus GSK3377794 n=13 participants at risk Eligible participants were leukapheresed to manufacture autologous NY-ESO-1c259 T cell receptors (TCR) bearing T-cells. Participants underwent lymphodepleting chemotherapy; cyclophosphamide 600 mg/m\^2/day plus fludarabine 30 mg/m\^2/day on day -7 through day -5 followed by a single infusion of GSK3377794 on Day 1.	Standard Lymphodepletion Dose Plus GSK3377794 n=10 participants at risk Eligible participants were leukapheresed to manufacture autologous NY-ESO-1\^c259 TCR bearing T-cells. Participants underwent lymphodepleting chemotherapy consisting of cyclophosphamide 900 mg/m\^2/day starting on day -7 through day -5 plus fludarabine 30 mg/m\^2/day on day -8 through day -5 followed by a single infusion of GSK3377794 on Day 1.
Cardiac disorders Cardiac arrest	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	0.00% 0/10 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Gastrointestinal disorders Abdominal pain	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	0.00% 0/10 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
General disorders Pyrexia	0.00% 0/13 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	10.0% 1/10 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Blood and lymphatic system disorders Anaemia	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	0.00% 0/10 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Blood and lymphatic system disorders Neutropenia	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	0.00% 0/10 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Immune system disorders Cytokine release syndrome	23.1% 3/13 • Number of events 3 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	50.0% 5/10 • Number of events 5 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Infections and infestations Pneumonia	0.00% 0/13 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	10.0% 1/10 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Investigations Neutrophil count decreased	0.00% 0/13 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	10.0% 1/10 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Investigations Platelet count decreased	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	10.0% 1/10 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Investigations Transaminases increased	0.00% 0/13 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	10.0% 1/10 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Metabolism and nutrition disorders Dehydration	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	0.00% 0/10 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Musculoskeletal and connective tissue disorders Back pain	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	0.00% 0/10 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Malignant neoplasm progression	0.00% 0/13 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	10.0% 1/10 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Respiratory, thoracic and mediastinal disorders Pleural effusion	7.7% 1/13 • Number of events 1 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	10.0% 1/10 • Number of events 2 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.
Skin and subcutaneous tissue disorders Rash maculo-papular	0.00% 0/13 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.	30.0% 3/10 • Number of events 3 • All cause mortality, non-serious adverse events (Non-SAEs) and serious adverse events (SAEs) were collected up to 30 months. All cause mortality, SAEs and non-serious adverse events were reported for the Intent-to-Treat (ITT) population, which included all participants who underwent leukapheresis.