Future Directions, Biomarkers, and Emerging Trials in HER2 Positive and HER2-Low Metastatic Breast Cancer

This final scenario segment looks ahead to evolving strategies following progression on multiple HER2-directed therapies. The panel discusses later-line options, including additional ADCs, chemotherapy combined with HER2 blockade, and clinical trial participation, particularly in the absence of actionable genomic alterations. The limited current role of biomarkers such as ERBB2 amplification or HER2 mutations in ctDNA is acknowledged, with consensus that they remain largely prognostic rather than predictive in routine practice. Attention then turns to ongoing and emerging trials exploring novel ADCs, bispecific antibodies, HER2-mutant strategies, and HER2-low–directed approaches. This segment underscores optimism about continued innovation while reinforcing that evidence-based sequencing, clinical trial enrollment, and careful patient selection remain essential as the treatment landscape continues to expand.