Complete Response Letter for sBLA for Keytruda in high-risk early-stage triple-negative breast cancer (TNBC) – Merck Inc.

Merck Inc., announced that the FDA has issued a Complete Response Letter (CRL) regarding Merck’s supplemental Biologics License Application (sBLA) seeking approval for Keytruda, the company’s anti-PD-1 therapy, 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.

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.

This CRL does not impact any current approved indications for Keytruda, including the indication for Keytruda in combination with chemotherapy for the treatment of patients with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (Combined Positive Score [CPS] ?10), as determined by an FDA-approved test. This indication is approved under accelerated approval based on progression-free survival. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials.