Earnings Conference Call & Webcast at 5:00 pm ET

Cubist Pharmaceuticals, Inc. (NASDAQ: CBST) will issue its first quarter 2014 financial results at 4:00 p.m. ET on Tuesday, April 22, 2014. In connection with this announcement, Cubist will host a conference call and live audio webcast presentation at 5:00 p.m. ET that same day to discuss its first quarter financial results, business activities, and financial outlook.

The quarterly earnings call will be available via phone and webcast. The conference call dial-in information is listed below. To access the webcast, please log on to the site 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 Q1 2014 FINANCIAL RESULTSTuesday, April 22, 2014 at 5:00 pm ET

U.S./Canada Attendee Dial-in: (855) 319-7654International Attendee Dial-in: (484) 756-4327Conference ID: 12504774

24-HOUR REPLAY U.S./CANADA: (855) 859-205624-HOUR REPLAY INTERNATIONAL: (404) 537-3406Conference ID: 12504774

CALL WILL ALSO BE BROADCAST LIVE, LISTEN ONLY, VIA THE WEB AT:https://cubist.webex.com/cubist/onstage/g.php?t=a&d=629311873Attendee Password: 04222014

Replay will be available for 90 days at www.cubist.com

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About Cubist

Cubist Pharmaceuticals, Inc. is a global biopharmaceutical company focused on the research, development, and commercialization of pharmaceutical products that address significant unmet medical needs in the acute care environment. Cubist is headquartered in Lexington, Massachusetts, with a central international office located in Zurich, Switzerland. Additional information can be found at Cubist’s web site at www.cubist.com. Also, connect with Cubist on Twitter @cubistbiopharma and @cubistcareers, LinkedIn, or YouTube.

INVESTORS:Cubist Pharmaceuticals, Inc.Eileen C. McIntyre, 781-860-8533eileen.mcintyre@cubist.comorMEDIA:Cubist Pharmaceuticals, Inc.Julie DiCarlo, 781-860-8063Senior Director, Corporate Communicationsjulie.dicarlo@cubist.com