Merrimack Pharmaceuticals and sanofi-aventis announced that the first patient has received an initial dose in a Phase 2 study combining MM-121 with Aromasin (exemestane) for the treatment of breast cancer. This multiple site study will evaluate whether the combination of MM-121 and exemestane is more effective than exemestane alone in postmenopausal women with locally advanced or metastatic estrogen receptor positive (ER+) and/or progesterone receptor positive (PR+), HER2-negative breast cancer.

MM-121 is a monoclonal antibody designed to block signaling of the ErbB3 receptor. It is a member of the ErbB family of receptors that play a critical role in cancer signaling.  

For more information call (617) 441-1000 or visit www.merrimackpharma.com.