Cubist Pharmaceuticals Highlights Presence At 43rd ICAAC.

Business Editors/Health/Medical Writers

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ICAAC 

LEXINGTON, Mass.--(BUSINESS WIRE)--Sept. 16, 2003

Over 30 Cubist-Related Posters Presented at Meeting

Cubist Pharmaceuticals, Inc. (Nasdaq: CBST) today provided details of key data presentations at this year's Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) taking place September 14-17 in Chicago, Illinois. More than 30 Cubist-related posters are being presented during the conference by both Cubist researchers and external investigators.

Poster L-737 highlights data from two multicenter, multinational, investigator-blinded, randomized Phase 3 studies of complicated skin and skin structure infections (cSSSIs) in adults. In the study, daptomycin (DAP) (4 mg/kg IV once daily) was compared with semi-synthetic penicillin (SSP) 1-4g q6h IV or vancomycin (VAN) 1g q12h IV for planned treatment of 7-14 days. Cubist recently obtained U.S. marketing approval for daptomycin (branded Cubicin(TM) in its injectable form; previously branded Cidecin(R)) for the treatment of cSSSI caused by Gram-positive bacteria. CUBICIN is the only once-daily, rapidly bactericidal antibiotic proven effective against both methicillin-resistant Staphylococcus. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA).

In the study, prior to randomization, a blinded investigator evaluated each subject and determined which comparator agent, either SSP or VAN, was to be given if randomized to the comparator arm. Patients at significant risk of having an MRSA infection were assigned to the VAN group, whereas patients having or suspected of having an MSSA infection were assigned to the SSP group. Data from this analysis demonstrated that the clinical success rates of DAP were statistically equivalent to either the VAN or the SSP subgroups.

In Poster A-1152, Elizabeth D. Hermsen, PharmD, of the University of Minnesota, College of Pharmacy, presented data from an in vitro study comparing the activity of daptomycin, cefazolin and vancomycin against the most common bacterial pathogens found in peritoneal dialysate fluid (PDF). Peritoneal dialysis-associated peritonitis (PDAP) is a problem in patients with renal disease; current therapy for PDAP typically includes cefazolin, or vancomycin where bacterial resistance is present. Interestingly, bacteria are unable to grow in PDF (the bacteria are in stationary or dormant phase), suggesting that the efficacy of cell wall-active antibiotics in PDF may be compromised. In this study, daptomycin produced a more thorough and more rapid killing than either cefazolin or vancomycin in PDF containing MRSA, MSSA, methicillin-susceptible Staphylococcus epidermidis (MSSE) and Streptococcus viridans, which account for approximately 50% of all PDAP clinical cases. Dr. Hermsen concluded that daptomycin may be a promising agent for use in PDAP and that her group will be pursuing clinical testing of daptomycin in patients with PDAP.

In additional poster presentations, data were presented comparing daptomycin's in vitro activity to other antibiotics, including nafcillin, vancomycin, linezolid, gentamicin, arbekacin, tigecycline, quinupristin/dalfopristin, doxycycline, rifampin, and others, against bacterial strains resistant to vancomycin, linezolid and other commercially available antibiotics.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of CUBICIN and other antibacterial drugs, CUBICIN should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. Patients receiving CUBICIN should be observed for the development of muscle pain or weakness and have creatine phosphokinase (CPK) levels monitored weekly. CUBICIN is not indicated for the treatment of pneumonia. The most commonly reported adverse events in the cSSS infection clinical trials in adults were constipation, nausea and headache.

CUBICIN is indicated 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 strains), Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis and Enterococcus faecalis (vancomycin-susceptible strains only).

For full prescribing information on CUBICIN for the treatment of complicated skin and skin structure infections, visit www.Cubicin.com.

About Cubist

Cubist Pharmaceuticals, Inc. is a biopharmaceutical company focused on the research, development and commercialization of antiinfective drugs. In the U.S., Cubist markets Cubicin(TM) (daptomycin for injection), the first antibiotic in a new class of antiinfectives, for the indication of complicated skin and skin structure infections caused by Gram-positive bacteria. Cubist's pipeline includes CAB-175, a next-generation parenteral cephalosporin antibiotic in Phase 1 trials, and an oral version of ceftriaxone (OCTX), a broad-spectrum cephalosporin antibiotic in pre-clinical development. 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 further identify, develop, and achieve commercial success for new products and technologies; (vi) Cubist's ability to establish and maintain successful manufacturing, sales and marketing, distribution, and development collaborations; (vii) legislative or regulatory changes adversely affecting Cubist or the biopharmaceutical industry; (viii) Cubist's ability to protect its intellectual property and proprietary technologies; (ix) 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 filings with the Securities and Exchange Commission, including those factors discussed under the caption "Risk Factors" in Cubist's recent SEC filings.

Cubicin is a trademark of Cubist Pharmaceuticals, Inc.

For more information on Cubist, please visit www.cubist.com