BioNTech's HER2-directed ADC shows modest benefit and higher lung toxicity in phase 3 trial

BioNTech reported results of its phase 3 DYNASTY-Breast02 trial evaluating trastuzumab pamirtecan (t-pam), an HER2-directed antibody-drug conjugate, in patients with HR-positive, HER2-low metastatic breast cancer.

The trial showed a statistically significant but modest improvement in progression-free survival compared with chemotherapy, which analysts said was largely expected and amounted to an incremental benefit.

Safety data revealed a higher incidence of interstitial lung disease (ILD) than seen in earlier studies of the ADC, raising concerns about the risk profile of the drug.

Based on these efficacy and safety findings, BioNTech concluded that t-pam is likely to provide limited benefit in the current treatment landscape.