Drug major Bristol-Myers Squibb and Gilead Sciences say they have obtained new data supporting bioequivalence of a new fixed-dose combination treatment for HIV, and will make another attempt to get the drug approved in the USA.

If approved, the new product would be the first complete highly-active antiretroviral therapy treatment (HAART) regimen for HIV available in a once-daily, oral pill.

The product combines B-MS’ Sustiva (efavirenz) and Gilead's Truvada (emtricitabine and tenofovir disoproxil) and was developed by co-formulating the antiretrovirals as individual layers in one tablet under a joint venture announced in December 2004.

Two earlier bioequivalence studies of the combination, reported in April and August 2005, failed to show that blood levels of the drugs were the same as if the products had been dosed individually, scuppering plans to file for approval of the new product.

The firms say they now anticipate filing a New Drug Application with the Food and Drug Administration (FDA) in the second quarter of 2005.

- Meanwhile, Gilead says it has completed a Phase I /II study of JTK-303, an oral HIV integrase inhibitor for HIV. The drug was licensed from Japan Tobacco in March 2005 and is also known as GS 9137. Gilead has exclusive rights to develop and sell the drug in all countries outside Japan.

The US company said it will present full data from the study ‘in the near future’ and that, based on the results, it expects to evaluate three doses of GS 9137, 20mg, 50mg and 125mg, each boosted with ritonavir 100mg in an upcoming Phase II trial.