Adaptive SBRT Plus Chemoimmunotherapy for ES-SCLC

This is a phase Ib, open-label, single-arm study in newly diagnosed patients with extensive stage SCLC, to test the safety of the adaptive addition of SBRT to combination therapy with durvalumab, platinum, and etoposide. Approximately 50 patients with ES-SCLC will be enrolled in this study in order to identify 20 patients with platinum refractory disease who do not show evidence of early response to chemoimmunotherapy. Eligible patients will complete 2 cycles of study treatment with durvalumab, platinum (cisplatin or carboplatin per investigator choice), and etoposide. Patients will then undergo standard of care restaging imaging. Those patients who have a partial or complete response will continue with combination systemic therapy, without additional intervention. In patients with less than a partial response (stable disease or progressive disease), SBRT will be given prior to cycle 3 of systemic therapy. The radiotherapy will be given in 5 fractions of 6 Gy to the primary tumor site. See study schema. Patients who undergo SBRT will resume systemic therapy within 2 weeks of completing SBRT and the interval between cycle 2 and cycle 3 should not exceed 6 weeks. Subsequent restaging imaging will continue as per standard of care. All patients will continue maintenance therapy with durvalumab until confirmed progressive disease.