Cubist Pharmaceuticals to Present at June 2010 Investor Conferences

Cubist Pharmaceuticals, Inc. (NASDAQ: CBST) today announced that company management will present at three investor conferences during June 2010 to discuss the company’s business activities, financial outlook, and current news.

• Michael Bonney, President and CEO, will present on Tuesday, June 8, at 8:00 a.m. Eastern Time at the Bank of America Merrill Lynch 2010 Smid (Small- and Mid-) Cap Conference at The Intercontinental Hotel in Boston. (Live audio with slides webcast.)
• David McGirr, SVP and CFO, will present on Tuesday, June 8, at 3:30 p.m. Eastern Time at the Jefferies 2010 Global Life Sciences Conference at the Grand Hyatt Hotel in New York City. (Live audio with slides webcast.)
• Robert Perez, EVP and COO, will present on June 17, at 8:40 a.m. Pacific Time at the 31^st Annual Goldman Sachs Healthcare Conference at the Hyatt Regency Century Plaza in Los Angeles. (Live audio-only webcast.)

The live webcasts of these presentations will be accessible through Cubist’s website at www.cubist.com in the Investor Relations Conference Calendar section. The webcasts will be available for a period of up 30 days after the presentations.

About Cubist

Cubist Pharmaceuticals, Inc. is a biopharmaceutical company focused on the research, development, and commercialization of pharmaceutical products that address unmet medical needs in the acute care environment. In the U.S., Cubist markets CUBICIN® (daptomycin for injection), the first antibiotic in a new class of anti-infectives called lipopeptides. Cubist also promotes MERREM® I.V. (meropenem for injection) in the U.S. under an agreement with AstraZeneca. The Cubist clinical product pipeline currently consists of a Phase 2 program, added with Cubist’s acquisition of Calixa Therapeutics Inc. in December 2009, focused on the development of a novel cephalosporin to address certain serious infections caused by multi-drug resistant (MDR) Gram-negative organisms; a Phase 2 program for the treatment of CDAD (Clostridium difficile-associated diarrhea); and a Phase 1 program intended to address the unmet medical need for a treatment for serious infections caused by MDR Gram-negative pathogens. Cubist is also working on several pre-clinical programs being developed to address areas of significant medical needs. These include an anti-infective program for the treatment of respiratory syncytial virus (RSV) in children, therapies to treat various serious bacterial infections, and agents to treat acute pain. Cubist is headquartered in Lexington, Mass. Additional information can be found at Cubist’s web site at www.cubist.com.

Cubist and CUBICIN are registered trademarks of Cubist Pharmaceuticals, Inc.

AstraZeneca and MERREM are trademarks of the AstraZeneca group of companies.