A once-daily pill that combines three drugs for HIV has been approved for sale by the US Food and Drug Administration, providing a convenient alternative to other drug regimens for managing the infection.

Atripla, developed by Bristol-Myers Squibb and Gilead Sciences, incorporates B-MS Sustiva (efavirenz) and Gilead’s Emtriva (emtricitabine) and Viread (tenofovir) in a single tablet. The drug will be made available in the US by next week, the companies said.

At one time highly-active antiretroviral therapy (HAART) for HIV/AIDS required patients to take handfuls of pills very day, but there has been a concerted effort by drugmakers to improve the formulation of the drugs to provide once-daily and fixed-dose combination products. The pay-off should be more convenience for the patient, as well as increased compliance with therapy that should provide tighter control of the virus and hold back the development of resistant strains.

Gilead already sells a combination product, Truvada, containing emtricitabine and tenofovir, which is scheduled to achieve $1 billion-plus in sales this year. Meanwhile GlaxoSmithKline sells a triple therapy product called Trizivir (zidovudine, lamivudine and abacavir) that is dosed twice a day and made $550 million in 2006.

But Atripla is the first once-daily triple therapy on the market, according to B-MS and Gilead, and incorporates the most commonly prescribed antiretroviral regimen in the USA for newly-diagnosed HIV patients.

Bristol-Myers and Gilead formed a US joint venture in 2004 to develop and commercialise the single-tablet regimen. They are currently in discussions with Merck & Co, which owns some ex-US rights to Sustiva, with a view to partnering Atripla outside the USA.

The availability of the product could also be a major event for HIV patients overseas.

"This key breakthrough will help in our battle against HIV/AIDS -- not only in the USA but in other countries through the President's Emergency Plan for AIDS Relief (PEPFAR) program," said Mike Leavitt, Secretary of Health and Human Services. PEPFAR is a $15 billion programme which aims to supply affordable medications to countries most affected by the HIV pandemic.