Acceptance Triggers $12 Million in Aggregate Milestone Payments to Momenta Under the Global Collaboration With Baxter

CAMBRIDGE, MA, USA I December 1, 2014 I Momenta Pharmaceuticals, Inc. (Nasdaq:MNTA), a biotechnology company specializing in the characterization and engineering of complex drugs, today announced the acceptance by the UK Medicines and Healthcare Products Regulatory Agency (MHRA) of a Clinical Trial Application (CTA) to initiate a clinical trial for M923, a biosimilar version of Humira® (adalimumab), in its collaboration with Baxter International’s biopharmaceutical business. Acceptance of the CTA triggers two milestones under the Baxter collaboration with an aggregate payment of $12 million. Momenta expects to receive the payment in December 2014.

“The European CTA acceptance for M923, our biosimilar version of Humira, represents a significant achievement by Momenta and Baxter in using the biosimilar regulatory pathway in an effort to expand patient choice,” said Craig A. Wheeler, President and Chief Executive Officer of Momenta Pharmaceuticals. “We look forward to the initiation of the clinical study in first quarter of 2015.”

Momenta is using its innovative technology to create a strong pipeline of biosimilars and potentially interchangeable biologics – a completely new segment of the biologics market. Momenta and Baxter have an ongoing collaboration for the worldwide development and commercialization of several biosimilar candidates at various stages of development, including M923 and M834.

About M923, a biosimilar version of Humira® (adalimumab)

M923 is a biosimilar version of Humira® (adalimumab) developed in collaboration with Baxter. The largest selling therapeutic on the market today, Humira is a transformative therapy for patients with autoimmune/inflammatory diseases. Humira is used to treat many conditions including rheumatoid arthritis, juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis and plaque psoriasis.

About Momenta’s biosimilars program

Momenta is applying its complex systems analysis platform to obtain thorough analysis of its biosimilars in relation to the branded biologic. Current biosimilars are being developed and commercialized with an understanding that some aspects of the drug may be different from that of its brand name counterpart. These differences may lead to uncertainty as to how well the biosimilar can replicate the therapeutic effects of its branded counterpart and provide the same safety profile. Momenta is striving to remove that uncertainty and any qualitative product differences by creating thoroughly characterized products that are indistinguishable from the brand name drug.

About Momenta

Momenta Pharmaceuticals is a biotechnology company specializing in the detailed structural and functional analysis of complex drugs and is headquartered in Cambridge, MA. Momenta is applying its technology to the development of generic versions of complex drugs, biosimilar and potentially interchangeable biologics, and to the discovery and development of novel therapeutics for oncology and autoimmune indications.

To receive additional information about Momenta, please visit the website at www.momentapharma.com, which does not form a part of this press release. The company’s logo, trademarks, and service marks are the property of Momenta Pharmaceuticals, Inc. All other trade names, trademarks, or service marks are property of their respective owners.

SOURCE: Momenta Pharmaceuticals