WEDNESDAY, Aug. 5, 2026 (HealthDay News) -- For adults with virologically suppressed HIV-1, once-weekly oral islatravir-lenacapavir (ISL/LEN) is noninferior to once-daily oral bictegravir-emtricitabine-tenofovir alafenamide (B/F/TAF) for maintaining HIV viral load suppression, according to a study published online July 29 in the New England Journal of Medicine.
Jürgen K. Rockstroh, M.D., from the University Hospital Bonn in Germany, and colleagues conducted a phase 3, double-blind, randomized, active-controlled, noninferiority trial involving adults in 12 counties, in whom HIV-1 had been virologically suppressed for at least six months while they were receiving B/F/TAF, to examine the efficacy and safety of a switch to once-weekly oral ISL/LEN. A total of 607 participants were randomly assigned in a 1:1 ratio to receive ISL/LEN or to continue B/F/TAF for 96 weeks; for the alternative regimen, all received matched placebo.
At 48 weeks, the researchers found that an HIV-1 RNA level of 50 copies/mL or higher was reported in no participants in the ISL/LEN group and one participant (0.3 percent) in the B/F/TAF group; an HIV-1 RNA level of less than 50 copies/mL was reported in 284 and 280 (93.4 and 92.4 percent, respectively). At 48 weeks, the mean change in the CD4+ T-cell count was −10 and −18 cells/µL with ISL/LEN and B/F/TAF, respectively. Due to adverse events in 2.0 and 1.7 percent of participants in the ISL/LEN and B/F/TAF groups, respectively, the trial regimen was discontinued; serious adverse events occurred in 5.3 and 4.6 percent, respectively.
"The first-ever weekly oral therapy for the treatment of HIV could offer welcome relief from the burden of life-long daily pill-taking for people living with HIV," senior author Chloe Orkin, M.B., B.Ch., from Queen Mary University of London, said in a statement. "This is especially important for people that are experiencing stigma and people with other HIV-associated health conditions who are taking multiple other tablets."
Several authors disclosed ties to biopharmaceutical companies, including Gilead Sciences and Merck, which are developing islatravir-lenacapavir and funded the study.
