Phase 2 TROPiCS-03 Study Shows Sacituzumab Govitecan Has ‘Promising Efficacy’ for ES-SCLC

Sacituzumab govitecan “demonstrated promising efficacy” as a second-line therapy for extensive-stage small cell lung cancer (ES-SCLC), regardless of platinum sensitivity, according to results from the phase 2 TROPiCS-03 study.

Afshin Dowlati, MD, of the University Hospitals Seidman Cancer Center and Case Western Reserve University, in Cleveland, Ohio, and colleagues conducted the study and published their findings in the Journal of Thoracic Oncology.

The TROPiCS-03 trial is a multicohort, open-label basket study assessing the antibody-drug conjugate in solid tumors, including ES-SCLC. The trial included 43 patients with ES-SCLC who progressed after one prior line of platinum-based chemotherapy and anti-PDL1 therapy. Patients received sacituzumab govitecan 10 mg/kg on days one and eight of a 21-day cycle.

The primary endpoint of the study was investigator-assessed objective response rate (ORR), with secondary endpoints including investigator-assessed duration of response (DOR) and progression-free survival (PFS); blinded independent central review (BICR)-assessed ORR, DOR, and PFS; overall survival (OS); and safety.

The investigator-assessed ORR was 41.9%, with 18 confirmed partial responses at a median follow-up of 12.3 months (range, 8.1 to 20.1). The DOR was 4.73 months (95% CI, 3.52-6.7), with a PFS of 4.4 (95% CI, 3.81-6.11). The median OS was 13.6 months (95% CI, 6.57-14.78). The study investigators noted that “efficacy results by BICR assessment were similar.”

The study investigators also evaluated efficacy in patients with platinum-resistant and platinum-sensitive disease. The investigator-assessed ORR was 47.8% (95% CI, 26.8%-69.4%) among the 23 patients with platinum-sensitive disease, and 35% (95% CI, 15.4%-59.2%) in patients with platinum-resistant disease.

Grade 3 or higher treatment-emergent adverse events (TEAEs) were reported in 74.4% of patients, with one treatment-related TEAE—neutropenic sepsis—leading to death. However, no TEAE led to discontinuation of treatment with sacituzumab govitecan.

The authors concluded that these results show the antibody-drug conjugate “demonstrated promising efficacy in the second-line treatment of ES-SCLC, irrespective of platinum sensitivity,” with safety being “manageable and consistent with that observed in other [sacituzumab govitecan] studies.”

Source: Journal of Thoracic Oncology