FDA Approves Enhertu (T-DXd) for Early-Stage HER2+ Breast Cancer — Two Simultaneous Indications Including Neoadjuvant and Adjuvant Settings

On May 15, 2026, the FDA approved fam-trastuzumab deruxtecan-nxki (Enhertu, developed by Daiichi Sankyo and AstraZeneca) for two simultaneous early-stage HER2-positive breast cancer indications — the first time this antibody-drug conjugate has been cleared for curative-intent settings after transforming the metastatic landscape. Indication 1 (neoadjuvant): T-DXd followed by a taxane, trastuzumab, and pertuzumab regimen for adults with Stage II or III HER2-positive early breast cancer, supported by the Phase 3 DESTINY-Breast11 trial. Indication 2 (adjuvant): T-DXd as post-surgery treatment for adults with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant therapy (including taxane/trastuzumab-based regimens), supported by the Phase 3 DESTINY-Breast05 trial. T-DXd is an ADC that delivers the topoisomerase I inhibitor payload DXd with precision via a cleavable linker and bystander effect on neighboring tumor cells. This approval marks a profound expansion of the ADC platform from purely palliative to potentially curative therapy in one of the most common cancer diagnoses worldwide — approximately 30,000 US patients per year present with early-stage HER2+ breast cancer. Previously, neoadjuvant pertuzumab + trastuzumab + chemotherapy followed by T-DM1 for residual disease was the standard; T-DXd now replaces or supplements this pathway with a more potent ADC across both phases of early-stage treatment. The co-development approval for two simultaneous indications in the same NDA submission is operationally notable for the ADC regulatory pathway.