Cubist Pharmaceuticals Names Michael Wood, M.D., and Martin Rosenberg,

    Pharmaceutical Writers/Business Editors
    BIOWIRE2K

    LEXINGTON, Mass.--(BUSINESS WIRE)--March 9, 2005--Cubist Pharmaceuticals, Inc. (Nasdaq: CBST) today announced the appointment of two new members to its Board of Directors. Dr. Wood, Orthopedic Surgeon and retired President-emeritus of Mayo Foundation and Professor of Orthopedic Surgery, Mayo Clinic School of Medicine, brings extensive knowledge of the hospital patient care environment. Dr. Rosenberg, Chief Scientific Officer of the Promega Corporation, brings both extensive pharmaceutical industry experience and specific expertise in infectious disease drug discovery and development. Drs. Wood and Rosenberg joined the Cubist Board earlier today. With these additions, the Cubist Board includes eight directors.

    Michael B. Wood, M.D.

    Dr. Wood retired as President-emeritus of Mayo Foundation in 2004. His earlier roles with the Mayo Foundation included Chief Executive Officer, Trustee, and Director of the Mayo Regional Health System. Dr. Wood currently serves on the Boards of the Institute for Healthcare Improvement (Boston, MA), the Steris Corporation (Mentor, Ohio), Assistive Technology Group, Inc. (Naperville, IL), Visionshare, Inc. (St. Paul, MN), and the Malcolm Baldridge Foundation (Washington, D.C.) Dr. Wood has also served on numerous hospital boards of directors. Dr. Wood has authored or co-authored more than 200 peer-reviewed publications and book chapters, as well as 2 books, and has been the principal investigator of an NIH-funded grant. Dr. Wood is also past president of the Baldridge Foundation Board and the American Society of Reconstructive Micro-Surgery. Dr. Wood received his B.A. degree from Franklin and Marshall College, M.D., C.M. degree from McGill University and M. Sc. Degree from the University of Minnesota. He has also received an honorary D.Sc. degree from Franklin and Marshall College.

    Martin Rosenberg, Ph.D.

    Dr. Rosenberg joined Promega Corporation, where he is currently Chief Scientific Officer, after retiring in 2001 as Senior Vice President of Anti-Infectives Drug Discovery and Development at GlaxoSmithKline. He spent 20 years in the SmithKline R&D Organization, with roles including Senior Vice President of R&D. Dr. Rosenberg serves on a variety of academic and industry Scientific Advisory Boards and holds an adjunct Professorship at the University of Wisconsin, Department of Bacteriology, Madison, WI. Dr. Rosenberg is Editor-in-Chief of Current Opinions in Biotechnology, and Section Editor of the Journal of Bacteriology. Before joining SmithKline Pharmaceutical R&D he spent 10 years at the National Institute of Health and was a Section Chief in the National Cancer Institute. Dr. Rosenberg has also served as a member of the Science Advisory Board of the FDA. Awards Dr. Rosenberg has received include the Arthur S. Fleming Award, and the Penlabs Award in Microbiology. He has published more than 200 papers and is the named inventor on more than 50 issued patents. Dr. Rosenberg received his Ph.D. from Purdue and his postdoctoral training at Yale Medical School.
    "The rich experience and specific expertise that Drs. Wood and Rosenberg bring to the table will be of great value as Cubist focuses on both optimizing the commercial success of our IV antibiotic, Cubicin(R), and continuing to build the company's product pipeline, " said Lead Director, Dr. David Martin.

    About Cubist

    Cubist Pharmaceuticals, Inc. is a biopharmaceutical company focused on the research, development and commercialization of antiinfective products that meet unmet medical needs. In the U.S., Cubist markets Cubicin(R) (daptomycin for injection), the first antibiotic in a new class of antiinfectives called lipopeptides. CUBICIN is currently the only once-daily bactericidal antibiotic approved in the U.S. with activity against both methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) in complicated skin and skin structure infections. Cubist's pipeline includes HepeX-B(TM), a monoclonal antibody biologic currently in the second of two Phase 2 trials to determine its potential for the prevention of infection by the Hepatitis B virus (HBV) in liver transplant patients, and research efforts focused on novel members of the lipopeptide class of molecules and on natural products discovery. Cubist is headquartered in Lexington, MA.

    Cubist Safe Harbor Statement

    Statements contained herein that are not historical fact may be forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, and such statements are subject to a variety of risks and uncertainties. There are a number of important factors that could cause actual results to differ materially from those projected or suggested in any forward-looking statements made by Cubist. These factors include, but are not limited to: (i) the level of acceptance of CUBICIN by physicians, patients, third-party payors, and the medical community generally; (ii) Cubist's ability to continue to develop, secure additional regulatory approvals for, and successfully market, CUBICIN; (iii) Cubist's ability to manufacture CUBICIN on a commercial scale; (iv) commercialization of products that are competitive with CUBICIN; (v) Cubist's ability to discover or in-license drug candidates; (vi) Cubist's ability to successfully develop drug candidates in its pipeline, including HepeX-B; (vii) Cubist's ability to successfully commercialize any product or technology developed by Cubist; (viii) Cubist's ability to establish and maintain successful manufacturing, sales and marketing, distribution, and development collaborations; (ix) legislative or regulatory changes adversely affecting Cubist or the biopharmaceutical industry; (x) Cubist's ability to protect its intellectual property and proprietary technologies; and (xi) Cubist's ability to finance its operations. Additional factors that could cause actual results to differ materially from those projected or suggested in any forward-looking statements are contained in Cubist's recent filings with the Securities and Exchange Commission, including those factors discussed under the caption "Risk Factors" in such filings.

    Cubist and Cubicin are registered trademarks of Cubist Pharmaceuticals, Inc.; HepeX-B is a trademark of XTL Biopharmaceuticals Ltd.

    Additional information can be found at Cubist's web site at www.cubist.com

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CONTACT: Cubist Pharmaceuticals, Inc. Eileen McIntyre, 781-860-8533 Senior Director, Corporate Communications eileen.mcintyre@cubist.com

KEYWORD: MASSACHUSETTS INDUSTRY KEYWORD: BANKING PHARMACEUTICAL MEDICAL BIOTECHNOLOGY MANAGEMENT CHANGES SOURCE: Cubist Pharmaceuticals, Inc.

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