CROI 2026: Low levels of bNAbs detected in rectal tissue up to 46 weeks post infusion

Simon Collins, HIV i-Base

Low levels of the long-acting broadly neutralising antibody (bNAb) VRC07-523LS were detected in rectal tissue of six study participants in a cure-related study. [1]

Samples were collected 21–51 weeks post infusion showed both penetration and retention in tissue. Samples were also stained to see the intensity of antibody binding and this was reduced in the participant sampled at week 51, which matched levels in three control participants who hadn’t received bNAbs,

Although bNAb levels were likely to be sub-therapeutic (range 8.5 to 0.6 μg/mL), the researchers concluded that their results showed the importance of including tissue sampling in cure-related bNAb studies.

The analysis was a sub-study of a cure-related prime-boost vaccine study that also included two bNAbs and a treatment interruption. [2]

comment

Although the poster doesn’t define target bNAb levels, these were low and likely sub-therapeutic.

A bigger question however, is whether any other tissue sites might retain bNAb levels for even longer in some participants.

References

Wang C et al. bNAbs Detected in Tissue Up to 46 Weeks Post administration. CROI 2026, Denver. Poster abstract 367.
https://www.croiconference.org/abstract/1575-2026/ (abstract and poster)
ClinicalTrials.gov. Combinatorial Therapy to Induce an HIV Remission (NCT04357821)
https://clinicaltrials.gov/study/NCT04357821