EXHIBIT 99.1 RIGHTS AGREEMENT This Rights Agreement (this "AGREEMENT"), dated as of July 21, 1999, is by and between Cubist Pharmaceuticals, Inc. (the "COMPANY"), a Delaware corporation, and BankBoston, N.A. (the "RIGHTS AGENT"), a national banking...Rights Agreement • July 30th, 1999 • Cubist Pharmaceuticals Inc • Pharmaceutical preparations • Delaware
