Merck KEYTRUDA gets USFDA priority review for its Second Application

Kenilworth: Merck, known as MSD outside the United States and Canada, has announced that the U.S. Food and Drug Administration (FDA) has accepted and granted priority review for a new supplemental Biologics License Application (sBLA) for KEYTRUDA, Merck's anti-PD-1 therapy.

The application seeks accelerated approval of KEYTRUDA monotherapy for the treatment of adult and pediatric patients with unresectable or metastatic solid tumors with tissue tumor mutational burden-high (TMB-H) ≥10 mutations/megabase, as determined by an FDA-approved test, who have progressed following prior treatment and who have no satisfactory alternative treatment options. The FDA has set a Prescription Drug User Fee Act (PDUFA), or target action, date of June 16, 2020.

"From the start, biomarker research has been a critical aspect of our clinical program evaluating KEYTRUDA monotherapy," said Dr Scot Ebbinghaus, vice president, clinical research, Merck Research Laboratories. "TMB has been an area of scientific interest to help identify patients most likely to benefit from KEYTRUDA. We look forward to working with the FDA throughout the review process to help bring KEYTRUDA monotherapy to patients with cancer in the second-line or higher treatment setting, where options remain limited."

The application was based in part on results from the Phase 2 KEYNOTE-158 trial, which also supported Merck's 2017 FDA approval for KEYTRUDA as the first cancer treatment based on a biomarker, regardless of cancer type, in microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumors.

MSI-H is on the highest end of the TMB spectrum. Data from KEYNOTE-158 on the TMB-H patient population were presented at the European Society for Medical Oncology (ESMO) 2019 Congress.

KEYNOTE-158 is a multicenter, multi-cohort, non-randomized, open-label trial evaluating KEYTRUDA (200 mg every three weeks) in patients with solid tumors. Tissue TMB status was determined using the Foundation Medicine, Inc. FoundationOne®CDx assay.

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