Exploring trop-2-directed ADCs monotherapy and combination therapy in pretreated mTNBC: a real-world study.

Abstract

PURPOSE: Although Trop-2 antibody-drug conjugates (ADCs) have improved outcomes in pretreated metastatic triple-negative breast cancer (mTNBC), resistance remains common and the optimal combination strategy in routine practice is unclear. METHODS: In this retrospective real-world study, we identified patients with mTNBC from a health record-derived database who received sacituzumab govitecan or sacituzumab tirumotecan in the later-line setting between April 2020 and December 2025. Patients received at least two cycles of Trop-2 ADC therapy as monotherapy, plus a PD-1 inhibitor (dual-agent combination), or plus a PD-1 inhibitor and an antiangiogenic agent (triple-agent combination). RESULTS: Descriptively, the ORR was 57.1% in the triple-agent combination group, 38.5% in the dual-agent combination group, and 31.7% in the monotherapy group. Median follow-up was 15.2 months (95% CI, 8.7-20.6). Median progression-free survival (mPFS) was 15.4 months (95% CI, 5.3-NA) in the triple-agent combination group, 10.0 months (95% CI, 4.2-NA) in the dual-agent combination group, and 3.8 months (95% CI, 3.2-5.2) in the monotherapy group. Severe treatment-related toxicity was not increased in the combination groups. Exploratory analyses identified a genomic scoring system that may enable stratification of patients with a higher likelihood of benefiting from the triple-agent combination. CONCLUSION: To our knowledge, this study represents one of the earliest real-world evaluations of this triple-agent strategy in previously treated mTNBC, providing a basis for further prospective validation and biomarker-guided application.