Study finds long-acting injectable HIV treatment effective in people with high BMI

Virologic failure was uncommon among participants on long-acting injectable cabotegravir/rilpivirine and did not differ significantly by body mass index (BMI), according to a recent study—even though most participants who met the BMI threshold for obesity received their injections with standard size rather than the recommended longer needles.

About This Study

“Real world virologic outcomes in patients with elevated body mass index receiving long acting cabotegravir/rilpivirine” was published online on Nov. 27, 2024, in Clinical Infectious Diseases. The lead author is Christina Maguire, Pharm.D., of the Department of Pharmacy at Penn Presbyterian Medical Center in Philadelphia, Pennsylvania.

Key Research Findings

This retrospective, multi-center cohort study, conducted between 2021 and 2023, investigated the potential effect of body mass index on HIV control in 374 participants, 40% of whom had a BMI ≥30 kg/m² (the threshold for obesity), who were receiving long-acting cabotegravir/rilpivirine at one of five U.S. clinics. Three-quarters of participants were assigned male sex at birth, 65% of participants were Black, median age was 41 years, and 40% of participants smoked.

During a year of treatment, three participants had at least two consecutive viral loads ≥200 copies/mL (virologic failure). Two of these participants were in the high body mass index arm and both received their injections with standard (1.5 inch) needles. Longer needles (2 inches) are recommended for people with obesity to ensure that the medication is injected into muscle rather than fat. After switching treatment regimens, all three participants returned to viral loads <200 copies/mL.

Low-level viremia did not differ significantly between the arms, with 12% of participants with obesity and 9% of the other participants experiencing at least two consecutive viral loads between 50 and 200 copies/mL. Two more participants had a single such viral load (viral blip) and one participant stopped the study medication due to ongoing low-level viremia. Thirteen percent of all participants with viral loads ≥50 copies/mL received at least one injection late (beyond the seven-day window).

Discussion Highlights and Implications for Practice

Study limitations reported included a t sample size that was potentially too small to detect between-group differences, poor documentation of late injections, and variable injection techniques across sites.

Results show that an elevated body mass index does not preclude administration of long-acting injectable HIV treatment, study authors concluded. They called for further research into the impact of viral blips on long-term HIV control with long-acting, injectable cabotegravir/rilpivirine.

By Barbara Jungwirth