Cubist Pharmaceuticals Ranks No. 1 in The Boston Globe`s Annual Globe 100 List of Best Performing Companies

Cubist Lands Top Spot in First Appearance
LEXINGTON, Mass.--(Business Wire)--
Cubist Pharmaceuticals, Inc. (NASDAQ: CBST) today announced that it was ranked
first among the "Top 100" Massachusetts-based publicly traded companies by The
Boston Globe in its 21st annual "Globe 100" listing released today. Cubist is
only the third life sciences company in Massachusetts to appear at the top of
the Globe 100 rankings, and as a company that researches, develops, and brings
to market pharmaceutical products, the first of its kind to achieve this
distinction.

Michael W. Bonney, Cubist`s president and CEO, said: "Being #1 in the Globe 100
list of the best-performing public companies in Massachusetts is a remarkable
achievement made possible by the hard work and dedication of our employees, and
it is a further validation of our strategy of focusing on urgent unmet needs in
the acute care environment. Last year was another year of strong performance for
Cubist as reflected by today's recognition. The company grew both the top and
bottom line, while bringing in additional acute care assets and progressing
exciting and important pipeline programs from the company's own discovery
activities. The Company also met or exceeded all of its financial guidance for
the year."

About The Boston Globe's annual Globe 100 rankings

The 21st annual Globe 100 ranks Massachusetts-based public companies based on
financial data from the four quarters ending closest to December 31, 2008, and
for corresponding quarters a year earlier. To be eligible, the company must be
traded publicly for the entire 2008 calendar year on the New York Stock
Exchange, the NASDAQ or the American Stock Exchange and report revenue and
profit for both 2007 and 2008. Companies are ranked on four criteria: return on
average equity, one-year percentage change in revenue, one-year percentage
change in profit margin and 2008 revenue.

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. In July 2008, Cubist began promoting
MERREM® I.V. (meropenem for injection) in the United States. MERREM is an
established broad spectrum antibiotic developed by AstraZeneca. The Cubist
product pipeline includes ecallantide, a recombinant human protein in Phase 2
clinical trials - CONSERV-1 and the planned CONSERV-2 - for the reductionof
blood loss during cardiothoracic surgery, and two Phase 1 programs that address
unmet medical needs, one in CDAD (Clostridium difficile-associated diarrhea) and
the other in multi-drug resistant (MDR) Gram-negative infections. In addition,
the Company, in collaboration with Alnylam Pharmaceuticals, Inc. (Cambridge,
MA), has a pre-IND and a Phase 2 program underway in novel treatments for
respiratory syncytial virus infections using Alnylam`s RNA-interference
technology. 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.

AstraZeneca and MERREM are registered trademarks of the AstraZeneca group of
companies.

Cubist Pharmaceuticals, Inc.
Eileen C. McIntyre, 781-860-8533
Senior Director, Corporate Communications
eileen.mcintyre@cubist.com
or
Weber Shandwick
Tara Murphy, 617-520-7045
tmurphy@webershandwick.com

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