X0303 4 2010-11-22 0 0001103390 Ardea Biosciences, Inc./DE RDEA 0001131146 DAVIS STEPHEN 4939 DIRECTORS PLACE SAN DIEGO CA 92121 0 1 0 0 EVP & COO Common Stock 2010-11-22 4 S 0 351 21.9172 D 25117 D The sale of common stock reported in this Form 4 was effected pursuant to a Rule 10b5-1 plan dated as of September 23, 2010. The range of sales prices received was $21.74 to $22.13. Upon request by the SEC staff, the issuer, or any security holder of the issuer, full information will be provided regarding the number of shares purchased or sold at each separate price. Includes 468 shares acquired under the Ardea Biosciences, Inc. 2000 Employee Stock Purchase Plan on November 12, 2010. /s/ Christian Waage Attorney-in-fact for Stephen Davis 2010-11-22