Cubist Pharmaceuticals Q3 2008 Revenues Up 41%; Net Income Up 39%: Total Revenues $112.4 Million; CUBICIN® Net Product Revenues $110.6 Million

October 16, 2008
For more information: http://www.investorcalendar.com/IC/CEPage.asp?ID=133542

GAAP Basic and Diluted Net Income of $0.49 and $0.44 Per Share, Respectively NON-GAAP Basic and Diluted Net Income of $0.54 and $0.48 Per Share, Respectively

Earnings Conference Call & Webcast Today (With Slides) at 5:00 p.m. EDT
Lexington, MA, October 16, 2008 -- Cubist Pharmaceuticals, Inc. (NASDAQ: CBST) today reported results for the third quarter ended September 30, 2008. Cubist's total net revenues from CUBICIN® (daptomycin for injection) increased 45% from the prior year, from $76.3 million in the third quarter of 2007 to $110.6 million in the third quarter of 2008. U.S. net product revenue from CUBICIN was $109.2 million. Total revenues for the third quarter of 2008 increased 41% over the third quarter of 2007 from $79.8 million in the third quarter of 2007 to $112.4 million in the third quarter of 2008. Included in total revenues for the third quarter of 2008 is $1.4 million of service revenue relating to Cubist's exclusive agreement with AstraZeneca to sell and provide other support in the United States for MERREM® I.V. (meropenem for injection).

Net income for the third quarter ended September 30, 2008 on a GAAP basis was $27.9 million, or $0.49 and $0.44 per basic and diluted share, respectively, as compared to $20.0 million, or $0.36 and $0.32 per basic and diluted share, respectively, for the third quarter of 2007. Third quarter 2008 GAAP net income includes $2.9 million, or $0.05 and $0.04 per basic and diluted share net of tax, respectively, in stock-based compensation expenses.

Non-GAAP net income for the third quarter ended September 30, 2008, excluding the stock-based compensation expenses described above, was $30.8 million, or $0.54 and $0.48 per basic and diluted share, respectively.

As of September 30, 2008, Cubist had $373.1 million in cash, cash equivalents and investments. The total number of common shares outstanding at September 30, 2008 was 56,897,048.

Use of Non-GAAP Financial Measures
Cubist uses non-GAAP net income (loss) and non-GAAP net income (loss) per share data to improve its analysis of operational results and trends. Cubist's management also uses these non-GAAP figures to make financial and operational decisions as these numbers exclude non-operational activities and because management believes these measures are useful to investors because they provide greater transparency regarding Cubist's operating performance. These measures should not be considered an alternative to measurements required by GAAP, such as net income (loss) and net income (loss) per share, and should not be considered measures of our liquidity. In addition, these non-GAAP measures are unlikely to be comparable with non-GAAP information provided by other companies. A reconciliation between non-GAAP financial measures and GAAP financial measures are included in the tables accompanying this press release after the unaudited condensed consolidated financial statements.

CONFERENCE CALL & WEBCAST INFORMATION
Cubist will host a conference call and live audio webcast to discuss its third quarter 2008 financial results, business activities and financial outlook.

WHEN: Thursday, October 16, 2008 at 5:00 p.m. EDT

LIVE DOMESTIC & CANADA CALL-IN: 877-407-0778
LIVE INTERNATIONAL CALL-IN: 201-689-8565
24-HOUR REPLAY DOMESTIC & CANADA: 877-660-6853
24-HOUR REPLAY INTERNATIONAL: 201-612-7415
REPLAY PASSCODES (BOTH REQUIRED FOR PLAYBACK):
ACCOUNT #: 286 CONFERENCE ID #: 295809

CALL WILL ALSO BE BROADCAST LIVE, LISTEN ONLY, VIA THE WEB AT: www.cubist.com
Replay will be available for 30 days at www.cubist.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® (daptomycin for injection), the first antibiotic in a new class of anti-infectives called lipopeptides. The Cubist product pipeline includes ecallantide, a recombinant human protein in Phase 2 clinical trials for the prevention of blood loss during cardiothoracic surgery, and pre-clinical programs that address unmet medical needs in Gram-negative infections, CDAD (Clostridium difficile-associated diarrhea), and HCV (Hepatitis C infections). 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.

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For tables, please see full release at:
http://www.cubist.com/investor_relations/press/
For more information: http://www.investorcalendar.com/IC/CEPage.asp?ID=133542