Once-daily single-tablet HIV therapy developed
MedWire News: A single tablet containing four antiviral agents may be an effective initial once-daily therapy for adults infected with HIV, shows phase III clinical research.
"Development of single-tablet regimens is a key strategy to simplify highly active antiretroviral therapy, and should improve adherence and treatment outcomes for patients with HIV infection," say Brian Kearney (Gilead Sciences, Foster City, California, USA) and team.
They add that previous studies have demonstrated that patients show better treatment compliance and longer viral load suppression with simple, once-daily regimens than with complex multipill regimens.
In the first of two trials, led by Kearney, 708 previously untreated HIV-positive patients, with an HIV-1 RNA concentration (viral load) of at least 5000 copies/ml, were randomly assigned to receive treatment with a single tablet consisting of elvitegravir (EVG), cobicistat (COBI), emtricitabine (FTC), and tenofovir disoproxil fumarate (TDF; n=353) or one tablet containing ritonavir-boosted atazanavir (ATV/RTV) plus another tablet containing FTC and TDF (n=355).
After 48 weeks of treatment, an HIV-1 RNA concentration of no more than 50 copies/ml (the primary endpoint) was achieved by a similar percentage of patients in each group.
Specifically, 89.5% and 86.8% of patients on the EVG/COBI/FTC/TDF and the ATV/RTV plus FTC/TDF regimes, respectively, achieved the primary endpoint.
Adverse event rates were also similar among both groups, at respective rates of 3.7% and 5.1%.
Of note, abnormal liver function tests were more common among the single than multitablet groups.
The second trial, reported along with the first study in TheLancet, assessed the same primary endpoint among a group of 700 HIV-positive patients with a viral load of least 5000 copies/ml.
Of these patients, 348 were randomly allocated to 48 weeks of treatment with EVG/COBI/FTC/TDF and 352 were assigned to treatment with a conventional single-tablet regime consisting of efavirenz (EFV) and FTC/TDF.
As seen in the first study, the primary outcome was achieved at a similar rate among both groups, at 87.6% and 84.1% among EVG/COBI/FTC/TDF and EFV/FTC/TDF patients, respectively.
Paul Sax (Brigham and Women's Hospital, Boston, Massachusetts, USA) and co-authors report that rates of adverse events leading to treatment discontinuation were also similar among both treatment groups.
Nausea, however, was higher among the EVG/COBI/FTC/TDF (20.7%) than the EFV/FTC/TDF group (13.6%).
Editorialists Rik Schrijvers and Zeger Debyser (Katholieke Universiteit Leuven, Flanders, Belgium) write: "The accompanying two phase 3 studies show that Quad [EVG/COBI/FTC/TDF] has high efficacy and a good tolerability profile."
They conclude that the "absence of long-term safety data (especially for renal toxic effects) and resistance data, warrant further research."
By Lauretta Ihonor