FDA Grants Orphan Drug Status To Merrimack's Pancreatic Cancer Drug MM-141

(RTTNews) - Merrimack Pharmaceuticals, Inc. (MACK) said Wednesday that the U.S. Food and Drug Administration has granted orphan drug designation to their investigational drug candidate MM-141 for the treatment of pancreatic cancer.

MM-141 is a tetravalent bispecific antibody designed to block tumor survival signals by targeting receptor complexes containing IGF-1R and ErbB3. The IGF-1R and HER3 complexes both activate a major cellular signaling pathway that allows tumor cells to grow and develop resistance to therapies.

MM-141 is Merrimack's sixth oncology candidate to enter clinical development and is currently being tested in a Phase 1 dose-escalation clinical study. A Phase 2 study testing MM-141 in combination with nab-paclitaxel and gemcitabine in front line pancreatic cancer is expected to start in 2015.

The FDA's Office of Orphan Products Development designates orphan status to drugs and biologics intended for the safe and effective treatment, diagnosis or prevention of rare diseases/disorders that affect fewer than 200,000 people in the United States. The orphan drug designation will potentially provide Merrimack Pharmaceuticals with seven-year marketing exclusivity for MM-141 and other benefits if the drug is approved by the FDA.