ACHILLION PHARMACEUTICALS, INC. (a Delaware corporation) 9,600,000 Shares of Common Stock UNDERWRITING AGREEMENTUnderwriting Agreement • June 22nd, 2011 • Achillion Pharmaceuticals Inc • Pharmaceutical preparations • New York
Achillion Pharmaceuticals, Inc., a Delaware corporation (the “Company”), confirms its agreement with Merrill Lynch, Pierce, Fenner & Smith Incorporated (“Merrill Lynch”) and each of the other Underwriters named in Schedule A hereto (collectively, the “Underwriters,” which term shall also include any underwriter substituted as hereinafter provided in Section 10 hereof), for whom Merrill Lynch and Leerink Swann LLC (“Leerink Swann”) are acting as representatives (in such capacity, the “Representatives”), with respect to (i) the sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective numbers of shares of Common Stock, par value $0.001 per share, of the Company (“Common Stock”) set forth in Schedules A and B hereto and (ii) the grant by the Company to the Underwriters, acting severally and not jointly, of the option described in Section 2(b) hereof to purchase all or any part of 1.440,000 additional shares of Common Stock to cover overa
