Sanofi-Aventis, Merrimack Enter MAb Pact

Merrimack Pharmaceuticals, Inc. and Sanofi-Aventis signed an exclusive worldwide licensing agreement for the development and commercialization of MM-121, a fully human monoclonal antibody designed to block signaling of the ErbB3 receptor. MM-121 is currently in Phase I testing as a potential treatment for cancer.

SA will make an upfront payment of $60 million and will be responsible for all development costs. Merrimack is eligible for an additional $470 million in milestone payments as well as royalties on sales. Merrimack will develop MM-121 through Phase II for each indication and SA will be responsible for further development. Merrimack retains the right to co-promote the therapy in the U.S.

The ErbB3 receptor is a novel target known to be a key mediator of a signaling network that impacts a broad array of cancers. By targeting ErbB3, MM-121 is believed to have a broad application across cancer as both a monotherapy and in combination with other therapeutics.

“Merrimack’s expertise along with their knowledge of biologics development has allowed them to successfully identify ErbB3 as a promising target and rapidly bring MM-121 into clinical development,” said Marc Cluzel, senior vice president R&D, SA. “MM-121 is a pioneering monoclonal antibody which brings a new innovative approach to Sanofi-Aventis’ oncology portfolio. We are very excited to collaborate with Merrimack on the development of MM-121, which we believe is a very promising compound that will address a significant gap in treating cancer patients.”