Cubist Pharmaceuticals Launches New Product Web Site.

LEXINGTON, Mass. -- Cubist Pharmaceuticals, Inc. (NASDAQ: CBST), a leader in the development and commercialization of anti-infective therapies, today announced the launch of its new CUBICIN product web site at www.cubicin.com.

Healthcare providers can go to the site for specific content across a wide range of specialties that include Infectious Diseases, Internal Medicine, Nephrology, Surgery, Oncology, Outpatient and Pharmacy. An educational patient vignette is provided for each specialty, along with product information, prescribing information and an overview of CUBICIN clinical data to date. The site also features content specifically geared towards patients - background on MRSA and information about the Patient Assistance Services Program - that serves to educate and empower patients who are directed to the site by their physician.

The web site coincides with the launch of the new CUBICIN brand campaign: "Inside, Outside, On Your Side." The campaign acknowledges the MRSA threat that causes bacteremia and complicated skin infections both inside the hospital and outside in the community, and provides helpful information about treatment with CUBICIN both in-hospital and in outpatient infusion settings. Elements of the new campaign will be highly visible throughout the 45th Annual Meeting of the Infectious Diseases Society of America in San Diego this week.

Greg Stea, Cubist Vice President of Sales and Marketing commented: "We have already seen that many physicians, both infectious disease and other internal medicine specialists, are choosing CUBICIN for use in outpatient infusion settings. The multi-healthcare provider web site supports our efforts at Cubist to provide up to date information regarding CUBICIN's role in the treatment of MRSA for bacteremia and complicated skin infections both inside and outside the hospital."

About CUBICIN

CUBICIN is currently the only once-daily bactericidal antibiotic approved in the U.S. for the treatment of complicated skin and skin structure infections caused by susceptible strains of the following Gram-positive microorganisms: Staphylococcus aureus (including methicillin-resistant and methicillin susceptible strains), Streptococcus pyogenes, S. agalactiae, S. dysgalactiae subsp equisimilis and Enterococcus faecalis (vancomycin-susceptible strains only). CUBICIN is also approved in the U.S. as therapy for bloodstream infections (bacteremia), including right-sided endocarditis, caused by S. aureus. CUBICIN is not indicated for the treatment of pneumonia. Most adverse events reported in clinical trials were mild to moderate in intensity. The most common were anemia, constipation, diarrhea, nausea, vomiting, injection site reactions, and headache. To reduce the development of drug-resistant bacteria and maintain the effectiveness of CUBICIN, CUBICIN should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria susceptible to CUBICIN. For full prescribing information, visit www.cubicin.com.

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([R])(daptomycin for injection), the first antibiotic in a new class of anti-infectives called lipopeptides. The Cubist product pipeline includes pre-clinical programs that address unmet medical need in Gram-positive infections, Gram-negative infections, and CDAD (Clostridium difficile-associated diarrhea). Cubist is headquartered in Lexington, MA. Additional information can be found at Cubist's web site at www.cubist.com.

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