CROI

CROI 2025: Broadly neutralizing antibodies delay HIV rebound after ART stopped

March 14, 2025

Patients who received two long-acting broadly neutralizing monoclonal antibodies (bNAbs) to maintain viral suppression off ART avoided rebound for five months, according to results shared at the Conference on Retroviruses and Opportunistic Infections (CROI) 2025.

Study details: The randomized, placebo-controlled RIO trial evaluated the efficacy of two long-acting bNAbs, 3BNC117-LS and 10-1074-LS, in maintaining viral suppression during an analytic treatment interruption in individuals treated during early HIV infection. Participants were randomized 1:1 to receive either the bNAbs or placebo and were monitored for viral rebound.

Results: By week 20, significantly more participants who received bNAbs didn't experience viral rebound compared with those who received placebo (75% vs. 8.8%). Participants receiving bNAbs were 91% less likely to rebound (hazard ratio, 0.09; 95% confidence interval, 0.04-0.21; P<0.0001). Viral suppression was maintained in 13/34 participants in the bNAbs group at 48 weeks and 7/34 at 72 weeks, compared with 2/34 participants in the placebo group at both time points.

Source:

Fidler S, et al. “RIO: a randomized placebo-controlled study of two LS-bNAbs in people treated with early HIV.” CROI 2025; Abstract 107. https://www.croiconference.org/wp-content/uploads/sites/2/resources/2025/media/croi2025-media-monday-abstracts.pdf