Decoding the landscape of bispecific antibodies in breast cancer: insights from a comprehensive trial analysis

Bispecific antibodies (bsAbs) represent a novel therapeutic strategy for breast cancer by leveraging diverse mechanisms of action (MOA) to overcome the limitations of conventional therapies. However, systematic analyses of bsAbs in breast cancer remain scarce. Based on the Trialtrove database (search up to September 7, 2025), we identified 193 eligible clinical trials investigating bsAbs in breast cancer. Our analysis reveals a significant surge in trials beginning in 2019, peaking in 2023. While most trials are in early phases (73.58%), the emergence of Phase III studies since 2023 signals a maturation trend. Immune checkpoint modulation dominates (64.77%), with PD-1/PD-L1 blockade as the leading strategy, followed by HER2-targeting bsAbs. Completed trials with positive outcomes highlight PD-1-based and HER2-targeted bsAbs as the most promising candidates. These findings provide a data-driven roadmap for bsAbs development in breast cancer, emphasizing the need to optimize target combinations and identify predictive biomarkers.