Merck & Co., Inc. (MRK) on Monday announced that the U.S. Food and Drug Administration (FDA) has granted priority review status for Keytruda, the company's supplemental Biologics License Application (sBLA) for its anti-PD-1 therapy.

The company states that the FDA granted priority review with a Prescription Drug User Fee Act (PDUFA), or target action date, of March 8, 2017. Passed by Congress in 1992, the PDUFA allows the FDA to collect fees from drug manufacturers to fund the new drug approval process. Likewise, the sBLA will be reviewed under the FDA's Accelerated Approval program based on tumor response rate and durability of response, Merck says. (See also: A Primer on the Biotech Sector.)

While Keytruda is already approved in the U.S. for the treatment of patients with unresectable or metastatic melanoma, the New Jersey-based drug giant is looking to expand the label into the first-line treatment of patients with advanced non-small cell lung cancer whose tumors express PD-L1.

"The FDA's acceptance of this application represents an important advance for the field of immuno-oncology and is further evidence of Merck's commitment to identifying patients most likely to benefit from Keytruda treatment," said Dr. Roger M. Perlmutter, president of Merck Research Laboratories, in a statement. "We believe that patients whose tumors harbor DNA repair defects may be especially responsive to Keytruda, and we look forward to working with the FDA to bring this important new therapy to these very challenging treatment situations." (See also: Merck to Test Keytruda-Cancer Vaccine Combo.)

Keytruda is described as a humanized monoclonal antibody that works by increasing the ability of the body's immune system to help detect and fight tumor cells. Beyond melanoma, the drug is being studied for more than 30 forms of cancer, including breast, ovarian, head and neck.

Merk shares were trading slightly higher in the pre-market session Monday, up 0.35%. The stock has risen about 18% year to date, compared with an 8.29% rise in the S&P 500 (SPX) index. (See also: Merck Bumps Its Dividend Higher.)

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