Lead Daiichi/Merck ADC Collab HER3-DXd Hit With CRL

Daiichi Sankyo Co., Ltd./Merck & Co., Inc.’s first collaborative antibody-drug conjugate (ADC) asset, patritumab deruxtecan (HER3-DXd), has received a Complete Response Letter (CRL) from the US Food and Drug Administration (FDA), the two firms disclosed on 26 June, the original action date under the Prescription Drug User Fee Act (PDUFA).

The CRL for the potentially first-in-class HER3-targeting therapy was related solely to (unspecified) findings in an inspection of a third-party manufacturing partner and “did not identify any issues with the...