U.S. regulators have granted Merck & Co's experimental treatment for advanced melanoma a "breakthrough therapy" designation, which could speed development and regulatory review of the product.
The medicine, whose chemical name is lambrolizumab, is also being tested against other forms of cancer. It belongs to a promising class of therapies that harness the body's immune system to find and attack cancer cells. It targets a protein called PD-1, or Programmed Death receptor.
The FDA created the "breakthrough therapy" designation earlier this year for medicines deemed likely to demonstrate "substantial improvement" over existing drugs.
Although it is intended to provide an easier path for drug development, Merck said it was not yet clear what specific benefits the designation would afford.
Merck shares slipped 0.6 percent in morning trading on the New York Stock Exchange to $48.36.
(Reporting by Ransdell Pierson; Editing by Gerald E. McCormick)