Multi-class HIV treatment consisting of just one pill once a day came step closer to becoming reality yesterday as drug companies Gilead Sciences and Bristol Myers Squibb (BMS) announced that they now have data showing that a fixed dose combination pill combining Gilead’s Truvada (tenofovir and FTC [emtricitabine]) with BMS’s efavirenz (Sustiva) provides the same amount of medicine in the blood to fight HIV as the separate components.
It is hoped that the new formulation of the drugs will help individuals adhere to their HIV therapy. Resistance to anti-HIV drugs can develop unless almost every prescribed dose is taken at the right time and in the right way. It is thought that the level of adherence needed for HIV therapy to be most effective is 95%, and studies have shown that many individuals fail to achieve or maintain this. There are numerous reasons why patients are unable to fully adhere to their HIV therapy, including simple forgetfulness, a desire to avoid side-effects and problems taking large numbers of pills. The early HIV combinations typically involved three seperate doses a day, each involving several pills. Since the late 1990s, efforts have been made to make HIV therapy easier to take, with reductions in both the number of doses and pills.
Gilead and BMS will be applying for formal US regulatory approval of the new coformulated pill by the middle of 2006. If approved, the new formulation will be the first once-daily HIV treatment comprising drugs from two classes of antiretrovirals.
Development of the Truvada and Sustiva coformulation started in the summer of 2004 and by 2005 three possible formulations had been further identified for further evaluation in bioequivalence studies.
In the current British and US HIV treatment guidelines, efavirenz combined with Truvada is one of the recommended antiretroviral combinations for individuals who have never taken anti-HIV therapy before.