Ardea Biosciences' Lead NNRTI for HIV, RDEA806, to Enter Phase 2a Proof-of- Concept Clinical Trial

CARLSBAD, Calif., Dec. 31 /PRNewswire-FirstCall/ -- Ardea Biosciences, Inc. (Nasdaq: RDEA) today announced that the Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom has authorized a Phase 2a clinical trial evaluating RDEA806, a novel non-nucleoside reverse transcriptase inhibitor (NNRTI), in patients with human immunodeficiency virus (HIV), the causative agent of AIDS.

"There is a clear unmet need for new NNRTIs that have the potential for a lower incidence of neuropsychiatric adverse effects, a high barrier to resistance, activity against resistant strains and the ability to be combined with other therapeutic agents," said Barry Quart, PharmD, President and CEO of Ardea Biosciences. "We believe that RDEA806 has the potential to offer a new option for patients with HIV and are excited to move this novel compound into Phase 2 clinical testing. We expect to obtain results from this trial in the first quarter of 2008."

The Phase 2a randomized, double-blind, proof-of-concept trial will be conducted in multiple European academic medical centers. The trial will evaluate the antiviral activity, pharmacokinetics, safety and tolerability of once daily and twice daily dose regimens of RDEA806 versus placebo in HIV-1 positive patients who are naive to antiretroviral treatment. The primary efficacy endpoint is the change from baseline in plasma viral load.

About RDEA806

RDEA806 is a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) for the potential treatment of HIV infection. Based on preclinical and clinical studies to-date, Ardea believes that RDEA806 possesses several attractive properties. These include: potential for potent antiviral activity against a wide range of HIV viral isolates, including those that are resistant to efavirenz (Sustiva(R), Bristol-Myers Squibb) and other currently available NNRTIs; a high genetic barrier to resistance; the potential to be administered in a patient-friendly, oral dosing regimen; limited pharmacokinetic interactions with other drugs; and the ability to be co-formulated with other HIV antiviral drugs.

About Ardea Biosciences, Inc.

Ardea Biosciences is focused on the discovery and development of small- molecule therapeutics for the treatment of viral diseases, cancer and inflammatory diseases. The Company plans to have active development programs with four new chemical entities (NCEs) in the clinic for three distinct indications by early 2008, with an additional one-to-two indications in inflammatory diseases planned for the first half of 2008.

Ardea's most advanced clinical development programs include: RDEA806, the Company's lead non-nucleoside reverse transcriptase inhibitor (NNRTI) for the treatment of HIV, which entered a Phase 2a clinical trial in the fourth quarter of 2007; RDEA119, a mitogen-activated ERK kinase (MEK) inhibitor for the treatment of cancer and inflammatory diseases, which is in a Phase 1 clinical trial in advanced cancer patients; and RDEA806 for gout, which is expected to enter a Phase 2 efficacy trial in the first half of 2008. Ardea also is developing a next-generation NNRTI and a next-generation MEK inhibitor, both of which are scheduled to enter first-in-human studies in early 2008.

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: Ardea's goals, including its goal of having active development programs with four new chemical entities (NCEs) in the clinic for three distinct indications by early 2008, with an additional one-to-two indications in inflammatory diseases in the first half of 2008, the expected properties and benefits of RDEA806 and its other compounds and the results of clinical and other studies. Risks that contribute to the uncertain nature of the forward-looking statements include: risks related to the outcomes of preclinical and clinical trials, risks related to regulatory approvals, delays in commencement of preclinical and clinical tests, and costs associated with internal development and in- licensing activities. These and other risks and uncertainties are described more fully in Ardea's most recently filed SEC documents, including its Annual Report on Form 10-K and 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. Ardea undertakes 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.