No current symptomatic, untreated, or uncontrolled brain metastases present Clinical or radiologic evidence of new, untreated, and/or progressive brain metastases prior to registration after induction systemic therapy. COHORT A: Previously untreated asymptomatic brain metastases Untreated or clinically active melanoma brain metastases. Participant has untreated brain or meningeal metastases. Active or untreated brain metastases Patients with untreated known brain metastases, or treated brain metastases that are clinically unstable History of brain metastases or who currently have treated or untreated brain metastases Untreated brain metastases Untreated brain metastases, if not planned to be treated in this course of radiation therapy Untreated brain metastases Known untreated or symptomatic brain metastases Untreated, progressing, or symptomatic brain metastases Known active and/or untreated brain metastases Symptomatic or untreated brain metastases One to 4 untreated metastatic brain lesions Metastatic melanoma or non-squamous NSCLC with untreated brain metastases Progressive, symptomatic untreated brain metastases Must not have untreated brain metastases Symptomatic and/or untreated Brain Metastases Untreated brain metastases Patients with untreated brain or meningeal metastases Untreated, progressing, or symptomatic brain metastases Untreated brain metastases (or local treatment of brain metastases within the last 6 months) Patients with brain metastases that are untreated, symptomatic, or require therapy to control symptoms; or any radiation, surgery, or other therapy, including those used to control symptoms, within 1 month of first dose Untreated or symptomatic brain metastases Untreated brain metastases Untreated or symptomatic brain metastases Patients with untreated brain metastases No symptomatic, untreated, or uncontrolled brain metastases present Known untreated brain metastases Active and/or untreated CNS disease or non-stable brain metastases Untreated or progressive brain metastases; patients with treated brain metastases not requiring chronic corticosteroids for symptom control are eligible Untreated or progressive brain metastases Previously untreated brain metastases. Patients with untreated or progressing brain metastases Patients with either untreated brain metastases or brain metastases treated within the past three months are ineligible Untreated and/or uncontrolled brain metastases. Untreated brain metastases (or local treatment of brain metastases within the last 6 months) Untreated brain metastases. Patients with active or untreated brain metastases; treated brain metastases must have been stable for at least 2 months Untreated or progressive brain metastases; patients with treated brain metastases not requiring chronic corticosteroids for symptom control are eligible Untreated brain metastases Patients with untreated symptomatic brain metastases will be excluded from this study; those with treated brain metastases or untreated but asymptomatic sub-centimeter brain metastases will be allowed as long as they are neurologically asymptomatic and off steroids Subjects with previously untreated or uncontrolled brain metastases. The participant has an untreated brain tumor Known brain metastases, or untreated meningeal/dural disease Untreated brain metastases. (Brain metastases that have been treated, which no longer require corticosteroid therapy and are without progression by MRI at least 6 weeks after definitive therapy are acceptable.) Has known untreated or symptomatic brain metastases; Untreated brain metastasis; patients with treated brain metastases who are off steroids are eligible Untreated brain metastases Known brain metastases that are untreated, symptomatic, or require therapy to control symptoms Brain metastases that are untreated or symptomatic or require any radiation, surgery,\n or steroid therapy to control symptoms from brain metastases within 1 month of\n randomization Known brain metastases that are untreated, symptomatic, or require therapy to control symptoms; or any radiation, surgery or other therapy to control symptoms from brain metastases within 2 months prior to first dose of MEDI4276. Untreated brain metastases; brain metastases =< 1 cm and not associated with any focal neurologic deficits are allowed Untreated brain metastases Active, untreated brain metastases Untreated brain metastases Patients with known untreated brain metastases Active or untreated brain metastases Known brain metastases that are untreated, symptomatic, or require therapy to control symptoms Untreated brain metastases (or local treatment of brain metastases within the last three months) Untreated brain metastases Brain metastases that are symptomatic or untreated or that require current therapy. Participant has untreated brain or meningeal metastases. Symptomatic and/or untreated brain metastases Untreated brain metastases Known brain metastases that are untreated, symptomatic, or require therapy to control symptoms Patients with known untreated and uncontrolled brain metastases are excluded. However, brain-imaging studies are not required for eligibility if the patient has no neurological signs or symptoms.