Cubist Pharmaceuticals to Announce Third Quarter 2008 Financial Results on Thursday, October 16, 2008

Cubist Pharmaceuticals, Inc. (NASDAQ: CBST) will issue its third quarter 2008 financial results at 4:00 p.m. EDT on Thursday, October 16^th, 2008. In connection with this announcement, Cubist will host a conference call and live audio webcast (with slides) at 5:00 p.m. EDT that same day to discuss its third quarter financial results, business activities and financial outlook.

As always, the quarterly earnings call will be available via phone and webcast. The phone call dial-in information is listed below. To access the webcast, please log on to the Cubist website at www.cubist.com at least 15 minutes prior to the start of the call to ensure adequate time for any software downloads that may be required.

A replay of the webcast and teleconference will be available on Cubist’s website beginning approximately three hours after the call.

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 II clinical trials for the prevention of blood loss during cardiothoracic surgery, and pre-clinical programs that address unmet medical needs in Gram-positive infections, 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.