VRC01, an investigations broadly neutralizing antibody (bNAbs), is found to be safe and effective in preventing HIV strains sensitive to that antibody, according to findings published by the National Institute of Health. While there were no safety concerns identified, VRC01 was unable to significantly reduce overall HIV acquisition.
The Antibody-Mediated Prevention Studies, sponsored and funded by the National Institute of Allergy and Infectious Disease, conducted two trials and included more than 4600 individuals with HIV to assess whether VRC01 was a safe and effective treatment option to prevent HIV acquisition. Men and transgender people who have sex with men were enrolled in the Americas and Europe, where subtype B is predominant; women were enrolled in the sub-Saharan Africa, where subtype C is dominant.
Study participants were randomly assigned to receive 10 intravenous infusions of VRC01 at a dose of 30 mg/kg, VRC01 at a dose of 10mg/kg, or placebo over the course of 80 weeks.
Results indicated the infusions were 75% effective and both VRC01 doses prevented acquisitions of HIV strains sensitive to the bNAb. In patients who acquired a VRC01-sensitive HIV strain during the trials, data showed that patients receiving placebo saw a higher HIV incidence rate compared to patients receiving VRC01 (0.86 per 100 person-years vs 0.2 per 100 person-years). A main determinant of how well the antibody worked for prevention of HIV acquisition was whether a patient was exposed to a VRC01-susceptible strain.
Overall, study authors found that only 30% of HIV strains within the testing regions were sensitive to VRC01. VRC01 infusions did not provide significant protection at 80 weeks compared to placebo.
“These observations suggest that more than 1 antibody likely will be needed to offer effective protection against the wide variety of HIVstrains,” the principle investigator, Larry Corey, MD, concluded.
Antibody infusions prevent acquisition of some HIV strains, NIH studies find. National Institutes of Health. January 26, 2021. Accessed February 17, 2021. https://www.nih.gov/news-events/news-releases/antibody-infusions-prevent-acquisition-some-hiv-strains-nih-studies-find