Merrimack to Present Pre-Clinical Data on MM-121 and MM-111 at the 101st Annual Meeting of the American Association for Cancer Research (AACR)

CAMBRIDGE, Mass., April 17 /PRNewswire/ -- Merrimack Pharmaceuticals, Inc. announced today that it will present pre-clinical data on MM-121 and MM-111, the two lead candidates in the company's pipeline of five novel cancer antibodies, at the 101st Annual Meeting of the American Association for Cancer Research (AACR) being held April 17 – 21, 2010, in Washington, D.C.

MM-121

Two posters will show pre-clinical data on MM-121, a monoclonal antibody designed to block signaling of the ErbB3 receptor. The ErbB receptor family has been known for years to have an impact on cancer signaling.  Merrimack gained insight into the critical role of the ErbB3 receptor in cancer biology through the use of their Network Biology platform that led to the novel design of MM-121.

Poster 1806 shows pre-clinical data on MM-121's efficacy as a single agent, and in combination with tamoxifen and paclitaxel, in ER+ and triple negative breast cancer studies.

Title:  Efficacy of MM-121 in ER+ and triple negative breast cancer studies

Poster Session:  Clinical Research 7

Number:  1806

Date/Time:  Monday April 19, 2010 9:00 AM - 12:00 PM

Location: Exhibit Hall A-C, Poster Section 32 Permanent Abstract

MM-121

Poster 3756 shows pre-clinical data on efforts to derive a predictive biomarker signature that identifies tumors responsive to MM-121.

Title:  Prediction of xenograft response to MM-121, an anti-ErbB3 inhibitor, using computational modeling and measurements of five biomarkers

Poster Session: Clinical Research 13

Number:  3756

Date/Time:  Tuesday April 20, 2010 9:00 AM - 12:00 PM

Location:  Exhibit Hall A-C, Poster Section 33

MM-111

MM-111 is a bispecific antibody designed to specifically inhibit ErbB3 signaling in ErbB2- overexpressing cancer cells. MM-111 binds to the critical ErbB2/ErbB3 cell receptor signaling complex and disables it from activating pAKT, an important mediator of cancer cell survival.

Poster 3485 shows pre-clinical data on the potent combinatorial effect of MM-111 and trastuzumab on inhibiting tumor cell growth driven by the ErbB2/3 signaling network

Title: MM-111, an ErbB2/ErbB3 bispecific antibody with potent activity in ErbB2-overexpressing cells, positively combines with trastuzumab to inhibit growth of breast cancer cells driven by the ErbB2/ErbB3 oncogenic unit

Poster Session:  Experimental and Molecular Therapeutics 22

Number:  3485

Date/Time:  Tuesday April 20, 2010 9:00 AM - 12:00 PM

Location:  Exhibit Hall A-C, Poster Section 21 Permanent Abstract

About Merrimack

Merrimack is a biopharmaceutical company dedicated to the discovery and development of novel medicines for the treatment of cancer and inflammation. The Company is advancing a robust pipeline of engineered therapeutics paired with molecular diagnostics. Merrimack's first two oncology candidates, MM-121, partnered with sanofi-aventis, and MM-111, are in Phase 1 clinical testing with multiple pre-clinical development and research stage programs in the pipeline. MM-121 and MM-111 are investigational drugs and have not been approved by the U.S. Food and Drug Administration or any international regulatory agency. The Company's proprietary Network Biology discovery platform, developed with the help of leading scientists from MIT and Harvard, integrates the fields of engineering, biology, and computing to enable mechanism-based, model driven discovery and development of both therapeutics and diagnostics. Merrimack is a privately-held company based in Cambridge, Massachusetts. For additional information, please visit http://www.merrimackpharma.com.

    
    
    Contact: Kathleen Petrozzelli, Corporate Communications, Merrimack,
             617-441-1043
    
             Betsy Stevenson, RaymondStevenson Healthcare Communications,
             860-984-1424

SOURCE Merrimack Pharmaceuticals, Inc.