CUBIST PHARMACEUTICALS INC - FORM 10-K - EX-32.1 - EXHIBIT 32.1 - February 26, 2010

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10-K - 10-K - CUBIST PHARMACEUTICALS INCa2196647z10-k.htm
EX-2.2 - EXHIBIT 2.2 - CUBIST PHARMACEUTICALS INCa2196647zex-2_2.htm
EX-10.31 - EXHIBIT 10.31 - CUBIST PHARMACEUTICALS INCa2196647zex-10_31.htm
EX-23.2 - EXHIBIT 23.2 - CUBIST PHARMACEUTICALS INCa2196647zex-23_2.htm
EX-32.2 - EXHIBIT 32.2 - CUBIST PHARMACEUTICALS INCa2196647zex-32_2.htm
EX-21.1 - EXHIBIT 21.1 - CUBIST PHARMACEUTICALS INCa2196647zex-21_1.htm
EX-31.2 - EXHIBIT 31.2 - CUBIST PHARMACEUTICALS INCa2196647zex-31_2.htm
EX-23.1 - EXHIBIT 23.1 - CUBIST PHARMACEUTICALS INCa2196647zex-23_1.htm
EX-31.1 - EXHIBIT 31.1 - CUBIST PHARMACEUTICALS INCa2196647zex-31_1.htm
EX-10.60 - EXHIBIT 10.60 - CUBIST PHARMACEUTICALS INCa2196647zex-10_60.htm
EX-10.57 - EXHIBIT 10.57 - CUBIST PHARMACEUTICALS INCa2196647zex-10_57.htm
EX-10.58 - EXHIBIT 10.58 - CUBIST PHARMACEUTICALS INCa2196647zex-10_58.htm
EX-10.61 - EXHIBIT 10.61 - CUBIST PHARMACEUTICALS INCa2196647zex-10_61.htm
EX-10.52 - EXHIBIT 10.52 - CUBIST PHARMACEUTICALS INCa2196647zex-10_52.htm
EX-10.56 - EXHIBIT 10.56 - CUBIST PHARMACEUTICALS INCa2196647zex-10_56.htm
EX-10.47 - EXHIBIT 10.47 - CUBIST PHARMACEUTICALS INCa2196647zex-10_47.htm
EX-10.54 - EXHIBIT 10.54 - CUBIST PHARMACEUTICALS INCa2196647zex-10_54.htm
EX-10.51 - EXHIBIT 10.51 - CUBIST PHARMACEUTICALS INCa2196647zex-10_51.htm
EX-10.59 - EXHIBIT 10.59 - CUBIST PHARMACEUTICALS INCa2196647zex-10_59.htm
EX-10.33 - EXHIBIT 10.33 - CUBIST PHARMACEUTICALS INCa2196647zex-10_33.htm
EX-10.55 - EXHIBIT 10.55 - CUBIST PHARMACEUTICALS INCa2196647zex-10_55.htm

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Exhibit 32.1

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO SECTION 906 OF
THE SARBANES-OXLEY ACT OF 2002

        In connection with the Annual Report of Cubist Pharmaceuticals, Inc. ("Cubist") on Form 10-K for the period ending December 31, 2009, as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Michael W. Bonney, President and Chief Executive Officer of Cubist, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that: (1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and (2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Cubist.

February 26, 2010

/s/ MICHAEL W. BONNEY
 Michael W. Bonney
 President and Chief Executive Officer		    



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CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

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