EXHIBIT 10.53 AMENDMENT TO CORVAS INTERNATIONAL, INC. 2000 EQUITY INCENTIVE PLAN APPROVED BY THE BOARD OF DIRECTORS FEBRUARY 24, 2003 WHEREAS, Corvas International, Inc. (the "Company") previously adopted the Corvas International, Inc. 2000 Equity Incentive Plan (the "Plan"); and WHEREAS, Section 13 of the Plan provides that the Plan may be amended by the Board of Directors of the Company and that the provisions relating to Options granted to Directors who are not Employees may be amended once every six months. NOW, THEREFORE, the Plan is amended as follows: 1. Section 7 of the Plan is amended to add the following additional paragraph to the end of Section 7: "(f) Notwithstanding Section 7(e) of the Plan or any other provision of the Plan or any relevant Option Agreement, the Options to purchase an aggregate of 48,000 shares of Common Stock granted on January 2, 2003 to the Directors who are not Employees, in the amounts and with the exercise price set forth on EXHIBIT A attached hereto shall become fully vested and exercisable on the closing of a corporate transaction described in Section 12(c) of the Plan." EXHIBIT A - ----------------------------------- ---------------------- ------------------------ ------------------ ---------------- NAME GRANT DATE GRANT TYPE OPTIONS GRANTED OPTION PRICE - ----------------------------------- ---------------------- ------------------------ ------------------ ---------------- Susan B. Bayh 1/2/2003 Non-Qualified 8,000 $1.338800 - ----------------------------------- ---------------------- ------------------------ ------------------ ---------------- M. Blake Ingle 1/2/2003 Non-Qualified 8,000 $1.338800 - ----------------------------------- ---------------------- ------------------------ ------------------ ---------------- J. Stuart Mackintosh 1/2/2003 Non-Qualified 8,000 $1.338800 - ----------------------------------- ---------------------- ------------------------ ------------------ ---------------- Burton E. Sobel 1/2/2003 Non-Qualified 8,000 $1.338800 - ----------------------------------- ---------------------- ------------------------ ------------------ ---------------- Michael Sorell 1/2/2003 Non-Qualified 8,000 $1.338800 - ----------------------------------- ---------------------- ------------------------ ------------------ ---------------- Nicole Vitullo 1/2/2003 Non-Qualified 8,000 $1.338800 - ----------------------------------- ---------------------- ------------------------ ------------------ ----------------