ASCENT-03: Sacituzumab Govitecan Versus Chemotherapy in First-Line Metastatic TNBC

In this segment, Dr. Yuan Yuan reviews the phase 3 ASCENT-03 trial evaluating first-line sacituzumab govitecan (SG) versus investigator’s choice of chemotherapy in patients with previously untreated, locally advanced unresectable or metastatic triple-negative breast cancer (TNBC) who were not candidates for immune checkpoint inhibitors. She outlines the study design, eligibility criteria, treatment regimens, and key efficacy findings. Median progression-free survival was 9.7 months with SG versus 6.9 months with chemotherapy, with a hazard ratio of 0.62. Interim overall survival was similar between the groups at 21.5 and 20.2 months, respectively, while objective response rates were 48% and 46%. The presentation also covers duration of response and complete response rates. Dr. Yuan discusses the safety profile, including the high incidence of treatment-related adverse events in both arms, grade 3 or higher toxicities, dose reductions, and treatment-related deaths. She emphasizes the importance of infection prevention, growth factor support, and early management of neutropenia and diarrhea. The segment concludes with key eligibility considerations, including the required interval following adjuvant therapy and the inclusion of only treated, stable central nervous system metastases. Dr. Yuan also highlights the substantial use of subsequent SG among patients initially assigned to chemotherapy, an important consideration when interpreting overall survival findings.