FDA Grants Orphan Drug Designation to Pancreatic Cancer Treatment

Merrimack Pharmaceuticals announced on Nov. 5, 2014 that FDA has granted orphan drug designation to its 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 (HER3). The IGF-1R and HER3 complexes both activate a major cellular signaling pathway that allows tumor cells to grow and develop resistance to therapies.

"Receiving orphan drug designation for MM-141 is an important regulatory advancement in the development of our clinical program," said Ulrik Nielsen, PhD, chief scientific officer and cofounder of Merrimack, in a press release. "Pancreatic cancer is an aggressive and devastating disease, with a five year survival rate of 6% and a low early detection rate. Merrimack is dedicated to changing the landscape of this disease for patients across all lines of therapy. We look forward to advancing the clinical development of MM-141 as we believe that it has the potential to significantly inhibit tumor survival signaling and address pathways of therapeutic resistance in this indication."

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. If FDA approves the drug, Merrimack Pharmaceuticals may receive seven-year marketing exclusivity for MM-141 and other benefits.

According to the company, MM-141 is a fully human tetravalent antibody that targets signaling of the PI3K/AKT/mTOR pathway driven through activation of IGF-1R and ErbB3/HER3. The PI3K/AKT/mTOR is a major pro-survival pathway that tumor cells use as a resistance mechanism to anticancer therapies. MM-141 is designed to interfere with this pathway by blocking ligand-induced signaling through the IGF-1R and ErbB3 receptors and degrading oncogenic receptor complexes. MM-141 is currently being tested in a Phase I dose-escalation clinical study. A Phase II study testing MM-141 in combination with nab-paclitaxel and gemcitabine in front line pancreatic cancer is expected to start in 2015.

Source: Merrimack