Phase 2 sacituzumab govitecan TROP2-directed SN-38 ADC + PD-L1 blockade maintenance in ES-SCLC

This Phase 2, open-label maintenance study tests whether adding sacituzumab govitecan (SG)—a TROP2-targeted monoclonal antibody–drug conjugate delivering the topoisomerase I inhibitor SN-38 (Gilead Sciences’ Trodelvy)—to ongoing PD-L1 immunotherapy can extend disease control after initial chemo-immunotherapy in extensive-stage small cell lung cancer (ES-SCLC). Participants receive SG on days 1 and 8 of each 21-day cycle plus either atezolizumab (Genentech/Roche) or durvalumab (AstraZeneca) on day 1, continuing up to 2 years or until progression/toxicity; imaging is front-loaded (CT about every 6 weeks early, plus scheduled brain MRI) to capture early disease-control signals. The key clinical angle is “maintenance intensification” with an ADC that may address residual chemo-resistant disease while PD-L1 blockade sustains immune pressure. For ES-SCLC, first-line treatment remains platinum–etoposide plus atezolizumab or durvalumab; after atezolizumab-based induction, lurbinectedin + atezolizumab is now an FDA-approved maintenance option, while durvalumab-based treatment generally continues with durvalumab maintenance. This trial tests sacituzumab govitecan as another maintenance-intensification strategy across either PD-L1 backbone.