News Release

SAN DIEGO--(BUSINESS WIRE)--Jul. 20, 2009-- Ardea Biosciences, Inc. (Nasdaq:RDEA) today announced that it has initiated a Phase 2b clinical trial of RDEA594, its lead product candidate in development for the management of hyperuricemia and gout. The Company also announced the selection of RDEA684, a next-generation URAT1 inhibitor, as a development candidate for the same indication.

The randomized, double-blind, placebo-controlled, dose-response study will evaluate the safety and serum urate-lowering effects of 200, 400 and 600 mg of RDEA594 in a total of 140 gout patients with hyperuricemia (uric acid levels of 8 mg/dL or more). The primary efficacy endpoint is the proportion of patients whose serum urate level is less than 6.0 mg/dL following four weeks of treatment. This study will be conducted at multiple sites in Europe and North America, with initial results expected by the end of 2009. The remaining studies in the planned Phase 2 program, including a Phase 2 study evaluating RDEA594 as an add-on to allopurinol in patients not responding adequately to allopurinol alone, a drug-drug interaction study with febuxostat (Uloric^®, Takeda Pharmaceutical Company Limited; Adenuric^®, Ipsen), and a study in patients with renal impairment, are expected to begin shortly.

“Our Phase 2 program is designed to demonstrate RDEA594’s broad clinical potential in a wide spectrum of gout patients, including first-line use and as add-on therapy in patients not achieving an adequate response to either allopurinol or febuxostat, and in patients with varying degrees of renal impairment,” commented Barry D. Quart, Pharm.D., Ardea’s president and chief executive officer. “The FDA approval of febuxostat earlier this year and the recent recommendation by the FDA’s Arthritis Advisory Committee for approval of pegloticase (Krystexxa™, Savient Pharmaceuticals) for treatment-refractory gout has demonstrated the importance of new urate-lowering therapies for treatment of patients suffering from gout.”

About RDEA594 and RDEA684

RDEA594, our lead product candidate for the treatment of hyperuricemia and gout, is a selective URAT1 transporter inhibitor that has successfully completed a Phase 2a proof-of-concept study in gout patients with hyperuricemia, as well as single- and multiple-ascending-dose Phase 1 studies in normal, healthy volunteers. Over 300 people have safely received RDEA594, either by direct administration or through administration of RDEA806, its prodrug. RDEA684, a next-generation URAT1 inhibitor, has been selected as a development candidate and has entered preclinical development in anticipation of a first-in-human clinical trial, which is expected to begin in 2010. Based on preclinical results, RDEA684 demonstrates many of the same positive attributes as RDEA594, but with more than 170-times greater potency against the URAT1 transporter.

About Ardea Biosciences, Inc.

Ardea Biosciences, Inc., of San Diego, California, is a biotechnology company focused on the development of small-molecule therapeutics for the treatment of gout, cancer, inflammatory diseases and human immunodeficiency virus (HIV). RDEA594, our lead product candidate for the treatment of hyperuricemia and gout, is a selective URAT1 transporter inhibitor in Phase 2 clinical development. Our next-generation development candidate for the treatment of hyperuricemia and gout, RDEA684, is currently in preclinical development in preparation for Phase 1 human clinical trials. RDEA119, a potent and specific inhibitor of mitogen-activated ERK kinase (MEK) and our lead product candidate for the treatment of cancer, is being developed under a global license agreement with Bayer HealthCare. RDEA119 is being evaluated as a single agent in a Phase 1 study in advanced cancer patients and in a Phase 1/2 study in combination with sorafenib (Nexavar^®; Bayer HealthCare, Onyx Pharmaceuticals) in advanced cancer patients. RDEA119 has also been evaluated for potential use in inflammatory diseases in a Phase 1 study in normal healthy volunteers. RDEA806, our lead product candidate for the treatment of HIV, is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that has successfully completed a Phase 2a study in HIV patients.

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding our plans and goals, the expected properties and benefits of RDEA594, RDEA684, RDEA119, RDEA806, and our other compounds and the timing and results of our preclinical, clinical and other studies. Risks that contribute to the uncertain nature of the forward-looking statements include risks related to the outcome of preclinical and clinical studies, risks related to regulatory approvals, delays in commencement of preclinical and clinical studies, costs associated with our drug discovery and development programs, and risks related to the outcome of our business development activities. These and other risks and uncertainties are described more fully in our most recently filed SEC documents, including our Annual Report on Form 10-K and our Quarterly Reports on Form 10-Q, under the headings "Risk Factors." All forward-looking statements contained in this press release speak only as of the date on which they were made. We undertake no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

Source: Ardea Biosciences, Inc.

Ardea Biosciences, Inc.
Jennifer Capuzelo, 858-652-6657
jcapuzelo@ardeabio.com