Ardea Biosciences, Inc. disclosed that the Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom has authorised a phase IIa clinical trial evaluating RDEA806, a novel non-nucleoside reverse transcriptase inhibitor (NNRTI), in patients with human immunodeficiency virus (HIV), the causative agent of AIDS.

"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 II clinical testing. We expect to obtain results from this trial in the first quarter of 2008," said, Barry Quart, president and CEO of Ardea Biosciences.

"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," he added.

The phase IIa, which is randomised, double-blind, proof-of-concept trial, would be conducted in multiple European academic medical centres. 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.

According to the company, 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, Bristol-Myers Squibb) and other currently available NNRTIs, high genetic barrier to resistance, 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.

Ardea Biosciences is a company focusing 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 programmes with four new chemical entities (NCEs) in the clinic for three distinct indications by early 2008, with additional one-to-two indications in inflammatory diseases planned for the first half of 2008.