1 SIGNAL PHARMACEUTICALS 5555 OBERLIN DRIVE SAN DIEGO, CA 92121 September 25, 1998 VIA EDGAR TRANSMISSION Securities and Exchange Commission 450 Fifth Street, N.W. Judiciary Plaza Washington, DC 20549 RE: SIGNAL PHARMACEUTICALS, INC. ("SIGNAL") REGISTRATION STATEMENT ON FORM S-1 (NO. 333-52901) APPLICATION FOR WITHDRAWAL Ladies and Gentlemen: The undersigned registrant hereby makes application, pursuant to paragraph (a) of Rule 477 under the Securities Act of 1933, as amended, to withdraw the above-referenced Registration Statement. This application is made on the grounds that, based on current market conditions, the undersigned registrant has determined that it is not advisable at this time to proceed with the proposed offering. If you should have any questions regarding this application, please contact Frederick T. Muto or Michael A. Newman of Cooley Godward LLP at (619) 550-6000. Sincerely, SIGNAL PHARMACEUTICALS, INC. By /s/ Alan J. Lewis Alan J. Lewis President and Chief Executive Officer cc: Mr. Bradley B. Gordon Frederick T. Muto, Esq. Michael A. Newman, Esq.