A preliminary study indicates that using a single boosted protease inhibitor instead of the standard regimen of 3 drugs for maintenance therapy may be an effective treatment for select patients with HIV infection, according to a study in the August 16 issue of JAMA, a theme issue on HIV/AIDS.
Susan Swindells, M.B.B.S., of the University of Nebraska Medical Center, Omaha, presented the findings of the study today at a JAMA media briefing at the International AIDS Conference in Toronto.
The long-term adverse effects, expense, and difficulty of sustained adherence to multidrug antiretroviral regimens have prompted studies of simpler therapies for human immunodeficiency virus type 1 (HIV-1) infection. Treatment cessation, intermittent therapy, and induction-maintenance (a few months of triple therapy followed by simplified therapy) regimens have been evaluated with mostly inferior results, according to background information in the article.
Virologic success (absence of failure) through 24 weeks of simplified therapy occurred in 91 percent of patients (31 of 34). Three participants experienced virologic failure at 12, 14, and 20 weeks after simplification. Resistance testing at failure did not identify protease inhibitor resistance mutations. Atazanavir concentrations in the blood at failure were low or below detection in 2 of 3 participants experiencing failure, indicating these patients may not have taken the prescribed doses. There were no treatment discontinuations for adverse events after simplification and no significant changes in CD4 cell counts.
"In this pilot study, the data suggest that simplified maintenance therapy with atazanavir-ritonavir alone in patients who have never experienced treatment failure may be efficacious in maintaining HIV-1 RNA suppression below 200 copies/mL for 24 weeks after discontinuing NRTIs," the authors write. "Maintenance therapy with a single boosted PI offers a treatment strategy with potentially less complexity, pill burden, long-term complications, and cost."