FDA slaps CRL on Byondis' [vic-]trastuzumab duocarmazine

The US Food and Drug Administration (FDA) has issued a complete response letter (CRL) for the Biological License Application (BLA) for [vic-]trastuzumab duocarmazine (SYD985), under development by Dutch clinical-stage biotech Byondis.

With this BLA, Byondis sought approval for its anti-HER2 antibody-drug conjugate (ADC) in HER2-positive unresectable locally advanced or metastatic breast cancer (MBC), a disease with a high unmet medical need.

According to the complete response letter, the FDA suspends the decision on the product’s approvability. The agency has requested additional information that requires time and resources that extend beyond the current evaluation period, Byondis explained.