TROPHY-U-01 Cohort 2: A Phase II Study of Sacituzumab Govitecan in Cisplatin-Ineligible Patients With Metastatic Urothelial Cancer Progressing After Previous Checkpoint Inhibitor Therapy.

Sacituzumab govitecan (SG) is a Trop-2-directed antibody-drug conjugate with an SN-38 payload, approved for patients with locally advanced (LA) or metastatic urothelial cancer (mUC) who progressed after platinum (PT)-based chemotherapy and a checkpoint inhibitor (CPI). Here, we report results from Cohort 2 of TROPHY-U-01 trial, evaluating the efficacy and safety of SG in patients with mUC. TROPHY-U-01 (ClinicalTrials.gov identifier: NCT03547973) is a multicohort, open-label phase II study. Cohort 2 includes patients with LA or mUC who have had progression or recurrence after a CPI and were cisplatin-ineligible at study initiation. Patients received SG 10 mg/kg on days 1 and 8 of 21-day cycles. The primary end point was objective response rate (ORR) per central review; secondary end points were clinical benefit rate (CBR), duration of response (DOR), and progression-free survival (PFS) per central review and safety. Cohort 2 included 38 patients (61% male; median age 72.5 years; 66% visceral metastases [29% liver]; 50% received previous PT-based chemotherapy as previous [neo]adjuvant therapy]). At a median follow-up of 9.3 months, ORR was 32% (95% CI, 17.5 to 48.7), CBR 42% (95% CI, 26.3 to 59.2), median DOR 5.6 months (95% CI, 2.8 to 13.3), median PFS 5.6 months (95% CI, 4.1 to 8.3), and median overall survival 13.5 months (95% CI, 7.6 to 15.6). Grade ≥3 treatment-emergent adverse events occurred in 87% of patients, most commonly neutropenia (34%), anemia (24%), leukopenia (19%), fatigue (18%), and diarrhea (16%). SG monotherapy demonstrated a relatively high ORR with rapid responses; this was feasible with a manageable toxicity profile in cisplatin-ineligible patients who had progression after CPI therapy. Limitations include a moderate sample size and lack of random assignment. These results warrant further evaluation of SG alone and in combinations in patients with LA/mUC.