An adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. A serious adverse event (SAE) is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug.

A DLT was defined as any Grade 3 or higher toxicity that occurs during the DLT evaluation period (From first dose of Study drug \[Day 1\] through 28 days after the administration of MEDI4736 and tremelimumab). The DLTs are: any Grade 4 immune-related adverse event (irAE), any Grade \>=3 non-irAE, \>= Grade 3 colitis, Grade 3 or 4 noninfectious pneumonitis irrespective of duration, Grade 2 pneumonitis, liver transaminase elevation \> 8 × upper limit of normal (ULN) or total bilirubin \> 5 × ULN. Immune-related AEs are defined as AEs of an immune nature (ie, inflammatory) in the absence of a clear alternative etiology.

Number of participants with clinical laboratory abnormalities reported as TEAEs are reported. Clinical laboratory abnormalities are defined as any abnormal findings in analysis of serum chemistry, hematology, and urine.

Number of participants with abnormal vital signs reported as TEAEs are reported. Abnormal vital signs are defined as any abnormal findings in the vital signs parameters (temperature, blood pressure \[BP\], pulse rate \[or pulse oximetry at screening\], and respiratory rate). Abnormal physical examinations are defined as any abnormal impact on measurements of height and weight.

Number of participants with abnormal electrocardiograms (ECGs) reported as TEAEs are reported. Abnormal ECGs are defined as any abnormal findings in heart rate, PR, RR, QRS and QT intervals from the primary lead of the digital 12-lead ECG.

The ECOG scale of performance status describes the level of functioning of participants in terms of their ability to care for themselves, daily activity, and physical ability. ECOG Performance Status Scorings are: 0= fully active, able to carry on all pre-disease performance without restriction; 1= restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature (for example, light house work, office work); 2= ambulatory and capable of all self-care but unable to carry out any work activities, up and about more than 50% of waking hours; 3= capable of only limited selfcare, confined to bed or chair more than 50% of waking hours; 4= completely disabled, cannot carry on any self-care, totally confined to bed or chair; 5= dead. The baseline performance status of participants is presented.

OR: best overall response (BOR) of confirmed complete response (CR) or partial response (PR) per RECIST v1.1. BOR: best response (CR, PR, stable disease \[SD\], progressive disease \[PD\], and not evaluable) among all overall responses recorded from date of randomization for Arm A, B, C participants or date of first dose of study drug for Arms D, E participants until progression, or last evaluable disease assessment or discontinuation from the study, whichever occurred first. CR: disappearance of all target/non-target lesions; PR: at least 30% decrease in sum of diameters (SOD) of target lesions from baseline; SD: neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD from smallest SOD on study; PD: at least 20% increase in SOD of target lesions from smallest sum on study (at least 5mm), appearance of one or more new lesions, substantial worsening in non-target disease, increase in tumor burden leading to discontinuation of therapy.

The PFS-6 is the 6-month progression-free survival rate, which was the percentage of participants who were progression free and alive at 6 months. PFS was defined as the time from the date of first dose of study drug for Arm A, B, and C participants or the date of first dose of study drug for Arm D and Arm E participants to the earlier of the dates of the first objective documentation of radiographic disease progression (per RECIST v1.1) or death due to any cause. PFS was censored at the date of their last evaluable tumor assessment. Kaplan Meier method was used to evaluate PFS-6.