FDA issues CRL on patritumab deruxtecan BLA

The US Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL) for the Biologics License Application (BLA) seeking accelerated approval of patritumab deruxtecan (HER3-DXd) for the treatment of adult patients with locally advanced or metastatic EGFR-mutated non-small cell lung cancer (NSCLC) previously treated with two or more systemic therapies.

The drug is under development by discoverer Japan’s Daiichi Sankyo (TYO: 4568) and US pharma giant Merck & Co (NYSE: MRK) .In October last year, Merck gained rights to three of Daiichi Sankyo’s DXd antibody drug conjugate (ADC) candidates: patritumab deruxtecan (HER3-DXd), ifinatamab deruxtecan (I-DXd) and raludotatug deruxtecan (R-DXd), for an initial $4 billion plus various contingent commitments that could add up to $22 billion, marking the biggest pharma  licensing deal ever.

The CRL results from findings pertaining to an inspection of a third-party manufacturing facility. The CRL did not identify any issues with the efficacy or safety data submitted. Patritumab deruxtecan is a specifically engineered potential first-in-class HER3 directed DXd antibody drug conjugate (ADC).