Cisplatin/Carboplatin and Etoposide With or Without Nivolumab in Treating Patients With Extensive Stage Small Cell Lung Cancer

PRIMARY OBJECTIVE: I. To evaluate the progression-free survival (PFS) of patients with extensive stage small cell lung cancer (ED-SCLC) treated with cisplatin/carboplatin and etoposide (CE) or CE with nivolumab (CEN) as front-line treatment. SECONDARY OBJECTIVES: I. To estimate overall survival of patients with ED-SCLC treated with cisplatin/carboplatin and etoposide (CE) or CE with nivolumab (CEN) as front-line treatment. II. To assess best overall response rate after treatment with CE with or without nivolumab as first line treatment. III. To evaluate the toxicity profile of nivolumab with CE. EXPLORATORY OBJECTIVES: I. To evaluate immune biomarkers and biomarkers correlatives. II. To evaluate serial circulating tumor deoxyribonucleic acid (DNA) and explore whether clinical outcome is associated with fluctuations in DNA levels following the administration of therapy. OUTLINE: Patients are randomized to 1 of 2 arms. ARM A: Patients receive nivolumab intravenously (IV) over 30 minutes on day 1, carboplatin IV over 30-60 minutes on day 1 or cisplatin IV over 60-120 minutes on day 1, and etoposide IV over 60-120 minutes on days 1-3. Treatment repeats every 21 days for up to 4 cycles in the absence of disease progression or unacceptable toxicity. Patients continue to receive nivolumab IV over 30 minutes every 2 weeks for up to 2 years. ARM B: Patients receive carboplatin IV over 30-60 minutes on day 1 or cisplatin IV over 60-120 minutes on day 1, and etoposide IV over 60-120 minutes on days 1-3. Treatment repeats every 21 days for up to 4 cycles in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months if the patient is less than 2 years from registration, every 6 months if the patient is 2-3 years from registration, and yearly for up to 5 years from study enrollment.