USA-based Merrimack Pharmaceuticals’ (Nasdaq: MACK) is a systems biology company focused on oncology.

Merrimack is applying its novel diagnostics and therapeutics in the clinic through the development of regimens for specific tumor types. These regimens couple diagnostic and therapeutic combinations that are targeted to improve patient outcomes.

Merrimack currently has six oncology therapeutics in clinical development, multiple product candidates in pre-clinical development and an active Systems Biology-driven discovery effort. These product candidates consist of a nanotherapeutic, a monoclonal antibody, a tetravalent antibody, a bispecific antibody designed to simultaneously bind to two different target cell surface receptors, an antibody-targeted nanotherapeutic and an oligoclonal antibody consisting of a mixture of three different antibodies.

Each of these product candidates is designed with specific characteristics that company scientists believe are well suited for the type of disease mechanism targeted. One of these, MM-121/SAR256212, is a fully human monocolonal antibody that targets the HER3 receptor. Merrimack’s Network Biology approach identified HER3 as a critical tumorigenic node in several types of cancer. Heregulin-induced signaling of HER3 activates cellular pathways promoting the development, growth and progression of cancer.

In addition, it is generally believed that HER3 activation serves as a compensatory mechanism by which cancer cells develop resistance to targeted therapies, many chemotherapies, and anti-hormonal therapies. MM-121 functions by inhibiting ligand-induced signaling through HER3 and activation of associated survival pathways.