Number of Participants randomized across sub studies are presented.

Overall survival was calculated as time from randomization to death. Confidence Intervals estimated using the Brookmeyer Crowley method.

A DLT is considered by the investigator to be clinically relevant, attributed event within first 28 days of intervention meeting the following criteria of toxicity, Hematologic: Febrile neutropenia, Grade 4 neutropenia of greater than (\>) 7 days in duration or requiring Granulocyte- Colony stimulating factor (G-CSF), Grade 4 anemia and Grade 3 thrombocytopenia with bleeding or Grade 4 thrombocytopenia; Non-hematologic: Grade 4 toxicity, Grade 3 pneumonitis, any greater than or equal to (≥) Grade 2 pneumonitis that does not resolve to less than or equal to (≤ ) Grade 1 within 3 days of the initiation of maximal supportive care, Grade 3 toxicity that does not resolve to Grade 1 or baseline within 3 days despite optimal supportive care and any Grade 2 ocular toxicity requiring systemic steroids, or any ≥ Grade 3 ocular toxicity.

The severity of all toxicities were graded using the National Cancer Institute- Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 5.0. Grade 1: Mild reaction; infusion interruption not indicated; intervention not indicated; Grade 2: Requires therapy or infusion interruption but responds promptly to symptomatic treatment or prophylactic medications indicated for ≤24 hours; Grade 3: Prolonged (i.e., not rapidly responsive to symptomatic medication and/or brief interruption of infusion) or recurrence of symptoms following initial improvement; hospitalization indicated for other clinical sequelae; Grade 4: Life-threatening; pressor or ventilatory support indicated; Grade 5: Death related to AE.

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. An SAE is defined as any untoward medical occurrence that, at any dose: results in death; is life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent disability/incapacity; is a congenital anomaly/birth defect and important medical events may jeopardize the subject or may require medical or surgical intervention/SOC to prevent one of the other outcomes mentioned before. AESIs are defined as events of potential immunologic etiology, including immune related AEs.

The number of participants with AE/SAE/DLTs leading to dose modifications/delays/withdrawals were summarized.

The severity of all toxicities were graded using the National Cancer Institute- Common Toxicity Criteria for Adverse Events (NCI-CTCAE) version 5.0. Grade 1: Mild reaction; infusion interruption not indicated; intervention not indicated; Grade 2: Requires therapy or infusion interruption but responds promptly to symptomatic treatment or prophylactic medications indicated for ≤24 hours; Grade 3: Prolonged (i.e., not rapidly responsive to symptomatic medication and/or brief interruption of infusion) or recurrence of symptoms following initial improvement; hospitalization indicated for other clinical sequelae; Grade 4: Life-threatening; pressor or ventilatory support indicated; Grade 5: Death related to AE.

The number of participants with severe- AE/SAE/DLTs leading to dose modifications/delays/withdrawals were summarized.

SBP and DBP were measured after 5 minutes of rest for the participant.

Temperature was measured after 5 minutes of rest for the participant.

Pulse rate was measured after 5 minutes of rest for the participant.

Respiratory rate was measured after 5 minutes of rest for the participant.

Oxygen saturation was measured using pulse oximeter after 5 minutes of rest for the participant.

Single 12-lead ECG was obtained using an automated ECG machine. ECG findings were categorized as: normal, abnormal - clinically significant (CS), or abnormal - not clinically significant (NCS), as determined by the investigator.

Blood samples were collected to assess change from Baseline in neutrophil, lymphocyte, monocyte, eosinophil, basophil and platelet counts.

Blood samples were collected to assess change from baseline in hemoglobin level.

Blood samples were collected to assess change from baseline in hematocrit level.

Blood samples were collected to assess change from baseline in Erythrocytes count.

Blood samples were collected to assess change from Baseline in albumin and total protein levels.

Blood samples were collected to assess change from baseline in creatinine and bilirubin levels.

Blood samples were collected to assess change from baseline in ALT, AST ALP, LDH levels.

Blood samples were collected to assess change from baseline in amylase and lipase levels.

Blood samples were collected to assess change in levels of urea, glucose, potassium, sodium and calcium from baseline.

Urine samples were collected to assess change from baseline in specific gravity of urine.

Urine samples were collected to assess change from baseline in pH of urine.

The dipstick test gives positive or negative results for protein, ketones, occult blood and glucose in urine. Positive test results were considered as abnormal. Number of participants with positive test results have been summarized.

Blood samples were collected to assess change from Baseline in TSH.

Blood samples were collected to assess change from Baseline in free T3.

Blood samples were collected to assess change from baseline in free T4.

For participants in Part 2, overall survival is defined as time from the date of randomization to the date of death due to any cause.

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. SAE is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent disability/incapacity, or is a congenital anomaly/birth defect, other situations which involve medical or scientific judgment or is associated with liver injury and impaired liver function. SAEs are subset of AEs. A summary of number of participants with any AEs and SAEs is presented. AEs were coded using the Medical Dictionary for Regulatory Affairs (MedDRA dictionary).

DLT is an AE that is considered by the investigator to be clinically relevant and attributed to the study therapy during the 28-day DLT period and meets at least one of the DLT criteria: Febrile neutropenia; Grade 4 neutropenia of \>7 days in duration or requiring Granulocyte Colony-stimulating Factor (G-CSF), anemia, thrombocytopenia, non-hematologic toxicity; Grade 3 thrombocytopenia with bleeding, pneumonitis, toxicity that does not resolve to Grade 1 or baseline within 3 days; Grade 2 ocular toxicity; Toxicity that results in permanent discontinuation of feladilimab during the first four weeks of treatment; any other event which in the judgment of the investigator and GSK Medical Monitor is considered to be a DLT.

Blood samples were collected for analysis of clinical chemistry parameters. Laboratory parameters were graded according to CTCAE v4.03. Grade (G) 0: None; G1: mild; G2: moderate; G3: severe or medically significant; G4: life-threatening consequences. Higher grade indicates greater severity and increase in grade was defined relative to Baseline grade. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including those from unscheduled visits. Only grade change data is presented for Baseline (B) and Worst-Case Post-Baseline (WCPB) as G0, G1, G2, G3, G4, and missing (M) here as "Parameter name, B GX, WCPB GX" where X=grade digit.

Normal ranges were 0.1 to 0.3 micromoles (umol)/liter (L) (direct bilirubin); 6 to 8.3 grams/L (protein); 100 to 250 international units (IU)/L (Lactate Dehydrogenase(LDH)); 2.3 - 4.1 picomoles/L (Free Triiodothyronine(T3)); 4.6 to 11.2 picomoles/L (Free Thyroxine(T4)); 0 and 0.04 microgram (ug)/L (Troponin I); 0 - 0.01 ug/L (Troponin T); 0.45 to 4.5 milliunits (Mu)/L (Thyrotropin(TSH)); and 6 to 24 millimoles/L (Urea). Participants were counted in worst case category that their value changes to low, normal or no change \[NC\] or high), unless there is NC in their category. Participants whose laboratory value category was unchanged (e.g. High to High) or whose value became normal, were recorded in "To Normal or No Change" category. Participants were counted twice if participant had values that changed To Low and To High, so percentages may not add to 100%.

Blood samples were collected for analysis of hematology parameters. Laboratory parameters were graded according to CTCAE v4.03. Grade (G) 0: None; G1: mild; G2: moderate; G3: severe or medically significant; G4: life-threatening consequences. Higher grade indicates greater severity and increase in grade was defined relative to Baseline grade. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including those from unscheduled visits. Only grade change data is presented for Baseline (B) and Worst-Case Post-Baseline (WCPB) as G0, G1, G2, G3, G4, and missing (M) here as "Parameter name, B GX, WCPB GX" where X=grade digit.

Normal ranges were 0.01 to 0.3\*10\^9 cells/L (basophils), 0 to 500 cells /L (eosinophils), 41 to 50 percentage of red blood cells (RBC) in blood (hematocrit), 1,000 - 4,800 lymphocytes per microliter (µL) of blood (lymphocytes), 80-100 femtoliters (fl) (erythrocytes, mean corpuscular volume), 2 to 8 percentage of WBC (monocytes), 40 to 60 cells/mcL (neutrophils) and Women: 4.2 to 5.4 million RBC/ microliter (mcL) of blood and Men: 4.7 to 6.1 million RBC/ mcL (erythrocytes count). Participants were counted in worst case category that their value changes to low, normal or no change \[NC\] or high), unless there is NC in their category. Participants whose laboratory value category was unchanged (e.g. High to High) or whose value became normal, were recorded in "To Normal or No Change" category. Participants were counted twice if participant had values that changed To Low and To High, so percentages may not add to 100%.

Urine samples were collected to assess urine glucose, ketones and occult blood using dipstick method. The dipstick test gave results in a semi-quantitative manner, and results for urinalysis parameters were recorded as negative, trace, 1+, 2+, 3+ indicating proportional concentrations in the urine sample. Baseline (Day 1) was defined as the most recent, non-missing value prior to or on the first study treatment dose date. Result for urinalysis parameters were recorded as no change/decreased and any increase.

Number of participants with dose modifications (including dose delays, dose escalations and infusion interruptions) were reported for Feladilimab.

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. SAE is defined as any untoward medical occurrence that, at any dose results in death, Is life-threatening, Requires inpatient hospitalization or prolongation of existing hospitalization, Results in persistent disability/incapacity or Is a congenital anomaly/birth defect, Other situations which involve medical or scientific judgment or is associated with liver injury and impaired liver function. SAEs are subset of AEs. A summary of number of participants with any AEs and SAEs is presented. AEs were coded using the MedDRA dictionary.

DLT is an AE that is considered by the investigator to be clinically relevant and attributed to the study therapy during the 28-day DLT period and meets at least one of the DLT criteria: Febrile neutropenia; Grade 4 neutropenia of \>7 days in duration or requiring Granulocyte Colony-stimulating Factor (G-CSF), anemia, thrombocytopenia, non-hematologic toxicity; Grade 3 thrombocytopenia with bleeding, pneumonitis, toxicity that does not resolve to Grade 1 or baseline within 3 days; Grade 2 ocular toxicity; Toxicity that results in permanent discontinuation of feladilimab monotherapy or in combination during the first four weeks of treatment; any other event which in the judgment of the investigator and GSK Medical Monitor is considered to be a DLT.

Blood samples were collected for analysis of clinical chemistry parameters. Laboratory parameters were graded according to CTCAE v4.03. Grade (G) 0: None; G1: mild; G2: moderate; G3: severe or medically significant; G4: life-threatening consequences. Higher grade indicates greater severity and increase in grade was defined relative to Baseline grade. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including those from unscheduled visits. Only grade change data is presented for Baseline (B) and Worst-Case Post-Baseline (WCPB) as G0, G1, G2, G3, G4, and missing (M) here as "Parameter name, B GX, WCPB GX" where X=grade digit.

Normal ranges were 6 to 8.3 grams/L (protein); 100 to 250 international units (IU)/L (Lactate Dehydrogenase(LDH)); 2.3 - 4.1 picomoles/L (Free Triiodothyronine(T3)); 4.6 to 11.2 picomoles/L (Free Thyroxine(T4)); 0 and 0.04 microgram (ug)/L (Troponin I); 0 - 0.01 ug/L (Troponin T); 0.45 to 4.5 milliunits (Mu)/L (Thyrotropin(TSH)); and 6 to 24 millimoles/L (Urea). Participants were counted in worst case category that their value changes to low, normal or no change \[NC\] or high), unless there is NC in their category. Participants whose laboratory value category was unchanged (e.g. High to High) or whose value became normal, were recorded in "To Normal or No Change" category. Participants were counted twice if participant had values that changed To Low and To High, so percentages may not add to 100%.

Blood samples were collected for analysis of hematology parameters. Laboratory parameters were graded according to CTCAE v4.03. Grade (G) 0: None; G1: mild; G2: moderate; G3: severe or medically significant; G4: life-threatening consequences. Higher grade indicates greater severity and increase in grade was defined relative to Baseline grade. Baseline (Day 1) was defined as latest pre-dose assessment with a non-missing value, including those from unscheduled visits. Only grade change data is presented for Baseline (B) and Worst-Case Post-Baseline (WCPB) as G0, G1, G2, G3, G4, and missing (M) here as "Parameter name, B GX, WCPB GX" where X=grade digit.

Normal ranges were 0.01 to 0.3\*10\^9 cells/L (basophils), 0 to 500 cells /L (eosinophils), 41 to 50 percentage of RBC in blood (hematocrit), 2 to 8 percentage of WBC (monocytes), 40 to 60 cells/mcL (neutrophils) and Women: 4.2 to 5.4 million RBC/mcL of blood and Men: 4.7 to 6.1 million RBC/ mcL (erythrocytes count). Participants were counted in worst case category that their value changes to low, normal or no change \[NC\] or high), unless there is NC in their category. Participants whose laboratory value category was unchanged (e.g. High to High) or whose value became normal, were recorded in "To Normal or No Change" category. Participants were counted twice if participant had values that changed To Low and To High, so percentages may not add to 100%.

Urine samples were collected to assess urine glucose, ketones and occult blood using dipstick method. The dipstick test gave results in a semi-quantitative manner, and results for urinalysis parameters were recorded as negative, trace, 1+, 2+, 3+ indicating proportional concentrations in the urine sample. Baseline (Day 1) was defined as the most recent, non-missing value prior to or on the first study treatment dose date. Result for urinalysis parameters were recorded as no change/decreased and any increase.

Number of participants with dose modifications (including dose delays, dose escalations, and infusion interruptions) were reported for Feladilimab