Setback for Merck, which gets CRL for Keytruda sBLA

The US Food and Drug Administration has issued a Complete Response Letter (CRL) regarding Merck & Co’s (NYSE: MRK) supplemental Biologics License Application (sBLA) seeking approval for Keytruda, for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC), in combination with chemotherapy as neoadjuvant (pre-operative) treatment, then continuing as a single agent as adjuvant (post-operative) treatment after surgery.

Merck is reviewing the letter and will discuss next steps with the FDA. An anti-PD-1 therapy, Keytruda is by far Merck’s biggest-selling drug, generated sales of $14.4 billion last year.

The application was based on pCR data and early interim event-free survival (EFS) findings from the Phase III KEYNOTE-522 trial, which is continuing to evaluate for EFS. Ahead of the Prescription Drug User Fee Act (PDUFA) action date for the application, the FDA’s Oncologic Drugs Advisory Committee voted 10-0 that a regulatory decision should be deferred until further data are available from KEYNOTE-522. The next interim analysis is calendar-driven and will occur in the third quarter of 2021.