Key Inclusion Criteria

• Histologically or cytologically confirmed SCLC
• Extensive disease, defined by at least one of the following:
• No limited disease (ie, no disease confined to the ipsilateral hemithorax, which can be safely encompassed within a tolerable radiation field)
• Extrathoracic metastases
• Malignant pericardial or pleural effusion
• Contralateral hilar adenopathy
• Measurable or nonmeasurable disease, as defined by modified RECIST
• Eastern Cooperative Oncology Group (ECOG) status 0 or 1
• ≥ 18 years old
• Life expectancy (with therapy) ≥ 3 months
• Adequate hematologic, hepatic, coagulation, renal, and metabolic function
• Diabetes, if present, must be controlled, with glycosylated hemoglobin (HbA1C) ≤ 8% and fasting glucose levels ≤ 160 mg/dL

Key Exclusion Criteria

• Prior chemotherapy, chemoradiation, or investigational agent for SCLC
• Prior radiotherapy to > 25% of the bone marrow
• Symptomatic or untreated central nervous system metastases (with exceptions)
• Currently or previously treated with biologic, immunologic or other therapies for SCLC
• Current serious or nonhealing wound or ulcer
• History of prior concurrent other malignancy (with exceptions)
• Any clinically significant medical condition other than cancer (eg, cardiovascular disease or chronic obstructive pulmonary disease), which could interfere with the safe delivery of study treatment or risk of toxicity