Thursday, July 16, 2009

Single daily poly-pill for HIV

In a prospective, randomized trial, a single daily tablet containing efavirenz, emtricitabine, and tenofovir (Atripla; Bristol Myers Squibb & Gilead Sciences LLC) maintained viral suppression in HIV-1 infected patients as well as the standard multiple-pill regimen.

The report of the study, published in the Journal of the Acquired Immune Deficiency Syndrome, notes that at baseline, all 300 participants were on stable antiretroviral therapy (ART) regimens, with viral loads of less than 200 copies/mL for at least 3 months. Their mean CD4 count was 540 cells/�L, and 96% of subjects had HIV-1 RNA <50>

On randomization, 203 were assigned to the Atripla regimen while 97 remained on their baseline regimen. The entire 48-week study was completed by 266 patients.

In the intent-to-treat analysis, it was found that at 48 weeks, the primary endpoint -- HIV-1 RNA below 200 copies/mL -- had been achieved by 89% of the patients in the single-tablet group versus 88% of those on unmodified antiretroviral regimens, "indicating noninferiority" of the newer approach.

Similarly, there was no significant difference between groups in maintenance of viral load below 50 copies/mL and no significant changes in CD4 cell counts within or between the two arms of the study.

Discontinuation rates were similar between the groups, but more patients in the single-tablet group discontinued due to adverse events, "most commonly for nervous system symptoms," according to the investigators.

Three patients in the single-tablet group and one in the control group had virologic failure.

"In summary," the researchers conclude, "patients who were stable and virologically suppressed while receiving a wide array of non-nucleoside reverse transcriptase inhibitor- and protease inhibitor-based antiretroviral regimens and had their treatment simplified to a single-tablet regimen of efavirenz, emtricitabine, and tenofovir maintained high rates of virologic suppression compared to those who continued their regimen unmodified."

Source: J Acquir Immune Defic Syndr 2009;51:163-174.

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