X0303 4 2010-08-09 0 0001103390 Ardea Biosciences, Inc./DE RDEA 0001384243 Quart Barry D 4939 DIRECTORS PLACE SAN DIEGO CA 92121 1 1 0 0 President and CEO Common Stock 2010-08-09 4 M 0 20000 3.90 A 61858 D Common Stock 2010-08-09 4 S 0 20000 20.2134 D 41858 D Employee Stock Option (Right to Buy) 3.90 2010-08-09 4 M 0 20000 0.00 D 2016-12-20 Common Stock 20000 190000 D The stock option exercise and sale of common stock reported in this Form 4 was effected pursuant to a Rule 10b5-1 plan dated as of June 11, 2009. Includes 343 shares acquired under the Ardea Biosciences, Inc. 2000 Employee Stock Purchase Plan on May 14, 2010. The range of sales prices received was $19.70 to $20.65. 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. 12.5% of the shares subject to the stock option vested and became exercisable on June 21, 2007, and 12.5% of the shares subject to the stock option vested and became exercisable on December 21, 2007. The remaining shares vest in equal monthly installments over the following 3 years. /s/ Barry D. Quart 2010-08-10