Merck Receives Complete Response Letter From US FDA for Supplemental Biologics License Application (sBLA) for KEYTRUDA® (pembrolizumab) in High-Risk Early-Stage Triple-Negative Breast Cancer (TNBC)

KENILWORTH, N.J.--(BUSINESS WIRE)-- Merck (NYSE: MRK), known as MSD outside the United States and Canada, today announced that the U.S. Food and Drug Administration (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 3 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.

About KEYTRUDA^® (pembrolizumab) Injection, 100 mg

KEYTRUDA is an anti-PD-1 therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.

Merck has the industry’s largest immuno-oncology clinical research program. There are currently more than 1,400 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient's likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.