Merrimack Pharma Presents Addl. Phase 2 Biomarker Data - Quick Facts

(RTTNews) - Merrimack Pharmaceuticals, Inc. (MACK) announced additional clinical and biomarker data from a Phase 2 study in ER/PR-positive, HER2-negative metastatic breast cancer showing that patients with high heregulin mRNA levels achieved a statistically significant benefit from combining the novel agent MM-121 with exemestane. Updated data from this biomarker subgroup, representing 45% of patients with metastatic breast cancer, showed a hazard ratio of 0.26 with a p-value of 0.003, the company said.

MM-121 is a fully human monoclonal antibody that targets ErbB3, a cell surface receptor that is activated by the ligand heregulin. During the second quarter of 2014, Merrimack regained worldwide rights to MM-121 and is pursuing a partnership to support the continued development of the program.

Also, clinical and biomarker data were presented from Phase 1 studies of MM-151, and MM-111.