- -------------------------------------- ------------------------------------ CUSIP No. 766559 10 8 13G Page 11 of 11 Pages - -------------------------------------- ------------------------------------ Exhibit 1 AGREEMENT Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13G need be filed with respect to the ownership by each of the undersigned of shares of Common Stock of Rigel Pharmaceuticals, Inc. This agreement may be executed in any number of counterparts, each of which shall be deemed an original. EXECUTED this 7th day of February, 2001. FRAZIER HEALTHCARE II, L.P. By: FHM II, L.L.C. Its General Partner By: Frazier Management, L.L.C. Its Managing Member By: Frazier & Company, Inc. Its Managing Member By: /s/ Alan D. Frazier ---------------------- Alan D. Frazier, President FHM II. L.L.C. By: Frazier Management, L.L.C. Its Managing Member By: Frazier & Company, Inc. Its Managing Member By: /s/ Alan D. Frazier ---------------------- Alan D. Frazier, President FRAZIER MANAGEMENT, L.L.C. By: Frazier & Company, Inc. Its Managing Member By: /s/ Alan D. Frazier ---------------------- Alan D. Frazier, President FRAZIER & COMPANY, INC. By:/s/ Alan D. Frazier Alan D. Frazier, President, Director and Shareholder /s/ Alan D. Frazier ------------------- Alan D. Frazier Page 11 of 11 pages