Sequential ADCs

This study examined the sequential treatment of breast cancer using two antibody-drug conjugates, Sacituzumab Govitecan (SG) and Trastuzumab Deruxtecan (TDXd). Data from about 80 patients revealed PFS was generally shorter for the second ADC, regardless of treatment order. Patients who received less prior treatment tended to fare better with sequential ADC therapy.

Notably, TDXd’s PFS remained stable whether it was administered before or after SG, while SG showed reduced PFS when used after TDXd. These findings suggest distinct resistance mechanisms for each ADC, highlighting the need for further research.

Clinically, TDXd remains the preferred option for patients with HER2+ disease due to its strong benefits. For those with HER2-low or ultra-low disease, SG may be considered before TDXd based on current data. This study provides valuable insights for optimizing sequential ADC therapy in breast cancer treatment, though it does not yet recommend changes in practice for HER2-positive patients.