US companies Bristol-Myers Squibb and Gilead Sciences have filed for approval of a product that combines the former's anti-HIV medications Sustiva and Truvada in a once-daily, single-tablet regimen.

Truvada is a fixed-dose product that contains two of Gilead's anti-HIV medications, Viread (tenofovir disoproxil fumarate) and Emtriva (emtricitabine), in a single once-daily tablet. Sustiva (efavirenz) is B-MS’ non-nucleoside reverse transcriptase inhibitor.

If approved by the FDA, the new single tablet regimen would be the first and only product that contains a complete highly-active antiretroviral therapy (HAART) regimen in a single once-daily tablet, intended for the treatment of HIV-1 infection in adults as a complete regimen or in combination with other antiretrovirals, according to the two firms.

The combination pill has been plagued by formulation problems mainly because Sustiva, when given as part of a combined pill, did not achieve the same medication level in the blood compared to a dose of B-MS' drug given alone. This issue has now been overcome, they said.

The US Department of Health and Human Services lists the combination of Truvada and Sustiva as one of the preferred non-nucleoside reverse transcriptase inhibitor–based regimens for treating newly-diagnosed HIV patients.