VAC-3S, an Immunoprotective HIV Vaccine Directed to the 3S Motif of gp41, in Patients Receiving ART: Safety, Dose and Immunization Schedule Assessment

Background: We have developed a novel immunotherapeutic vaccine (VAC-3S), comprised of 3S peptide, a highly conserved HIV gp41motif coupled to commercially used carrier and adjuvant. The 3S motif leads, by NKp44L expression on CD4, to apoptosis of uninfected CD4. In vitro, anti-3S antibodies (Ab) protect CD4 from apoptosis. In cohort studies, anti-3S Ab correlate with lack of CD4 decrease and/or disease progression. VAC- 3S primate proof-of-concept showed effect on immune and inflammatory biomarkers. Dose ranging studies, GLP toxicity, local tolerance studies were performed in rats and rat/mice, respectively