Vorolanib + Atezolizumab as Maintenance Therapy for Extensive-Stage Small Cell Lung Cancer

Inclusion Criteria: * Histologically or cytologically confirmed extensive stage small cell lung cancer without prior specific systemic therapy aside from induction with platinum, etoposide, and atezolizumab. Measurable disease is not required for eligibility. * Receipt of at least 3 cycles (and no more than 4 cycles) of platinum plus etoposide and atezolizumab during the induction phase, without tumor progression as determined by CT scan and brain MRI. Patients should be able to start the study treatment no more than 6 weeks from the last dose of induction chemo/immunotherapy. This period may be extended to 8 weeks in patients requiring brain radiotherapy after completion of induction chemo/immunotherapy for brain metastases. * At least 18 years of age. * ECOG performance status ≤ 1 * Normal bone marrow and organ function as defined below: * Absolute neutrophil count ≥ 1.5 K/cumm * Platelets ≥ 100 K/cumm * Hemoglobin ≥ 9.0 g/dL * Total bilirubin ≤ 1.5 x IULN * AST(SGOT)/ALT(SGPT) ≤ 2.5 x IULN (≤ 5 x IULN for patients with liver metastases) * Creatinine ≤ 1.5 x IULN OR measured or calculated creatinine clearance \> 50 mL/min for patients with creatinine levels \> 1.5 x IULN * Urine protein ≤ 1+ or urine protein to creatinine ratio ≤ 1; if UPC ratio is \> 1 on urinalysis, then 24-hour urine collection for protein must be obtained and level must be \< 1,000 mg for patient enrollment * aPTT and either INR or PT ≤ 1.5 x IULN unless participant is receiving antico…