Phase 3 study of KEYTRUDA monotherapy meets primary endpoint

Merck , known as MSD outside the United States and Canada, announced today that the pivotal Phase 3 KEYNOTE-048 trial investigating KEYTRUDA^® (pembrolizumab), Merck's anti-PD-1 therapy, for first-line treatment of recurrent or metastatic head and neck squamous cell carcinoma (HNSCC), met a primary endpoint of overall survival (OS) as monotherapy in patients whose tumors expressed PD-L1 (Combined Proportion Score (CPS) ≥20). Based on an interim analysis conducted by the independent Data Monitoring Committee (DMC), treatment with KEYTRUDA monotherapy in these patients resulted in significantly longer OS compared to cetuximab in combination with platinum chemotherapy (cisplatin or carboplatin) plus 5-Fluorouracil (5-FU), the current standard of care for HNSCC in the first-line treatment setting. At the time of the interim analysis, the dual-primary endpoint of progression-free-survival (PFS) for patients whose tumors expressed PD-L1 (CPS≥20) had not been reached. The safety profile of KEYTRUDA in this trial was consistent with that observed in previously reported studies involving patients with HNSCC. These results will be presented at an upcoming medical meeting and submitted to regulatory authorities worldwide.

Based on the recommendation of the DMC, the trial will continue with no changes to evaluate KEYTRUDA monotherapy and KEYTRUDA in combination with platinum chemotherapy (cisplatin or carboplatin) plus 5-FU.

"This interim analysis of KEYNOTE-048 trial has shown that KEYTRUDA monotherapy has the potential to help patients with head and neck cancer whose tumors express high-levels of PD-L1," said Dr. Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories. "We look forward to presenting these initial results from the KEYNOTE-048 trial at an upcoming medical meeting, and are grateful to the investigators and patients for their continued involvement in this important study."