MM-141 is a tetravalent bispecific antibody that blocks tumor survival signals by targeting receptor complexes containing IGF-1R and ErbB3 (HER3), which activate a major cellular signaling pathway that allows tumor cells to grow and develop resistance to therapies.
Merrimack chief scientific officer and co-founder Ulrik Nielsen said: "Receiving orphan drug designation for MM-141 is an important regulatory advancement in the development of our clinical program.
"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.
MM-141 is the company’s sixth oncology candidate to enter clinical development and is currently being evaluated in a Phase I dose-escalation clinical trial.
The company intends to start a Phase II trial in 2015, which will evaluate MM-141 in combination with nab-paclitaxel and gemcitabine in front line pancreatic cancer.