July 3, 2023

IAVI announces first doses in new clinical trial of innovative HIV vaccine candidate

Sequential immunization approach used furthers IAVI’s HIV vaccine development.

IAVI is pleased to announce the start of a new Phase I clinical trial, IAVI C107, to test the safety and immunogenicity of a booster immunization in a sequential HIV vaccine regimen. The first dose was administered on June 22 at Rockefeller University in New York, NY.

IAVI C107 Aurum Institute Klerksdorp microscope homepage

This small, open-label clinical trial builds on a prior trial, IAVI C101, which evaluated the first component of what is envisioned to be a sequential, multi-component vaccine regimen. The vaccine components being evaluated in IAVI C107 and IAVI C101 are elements of a multi-step approach to generating broad immunity to HIV. This approach envisions generating a broad immune reaction by priming the immune system with one adjuvanted vaccine and boosting with a second adjuvanted vaccine from the same family. The aim is for the introduction of these carefully sequenced immunogens to stimulate the immune system’s B cells to produce specific broadly neutralizing antibodies. The principal investigator (PI) of the clinical study is Marina Caskey, associate professor of clinical investigation at Rockefeller University, and the scientific PI is Rogier Sanders, professor of virology and vaccinology, Amsterdam University Medical Centers.

To that end, IAVI C107 trial will enroll 10 adults, all of whom received three doses of 300µg BG505 SOSIP.GT1.1 gp140 vaccine, adjuvanted, in IAVI C101; during IAVI C107 they will receive two doses of 100µg of BG505 SOSIP.664 gp140 vaccine, adjuvanted. The immunogens used in the two studies differ slightly, and a different adjuvant is used. The immunogen used in this study was designed by Rogier Sanders and John Moore, professor of microbiology and immunology at Weill Medical College of Cornell University. IAVI gratefully acknowledges Julie McElrath, head of the vaccine and infectious disease division at Fred Hutch, for facilitating the supply of the Access to Advanced Health Institute’s (AAHI) 3M-052-AF adjuvant formulation, using 3M Corporate’s 3M-052 adjuvant molecule. IAVI gratefully acknowledges the donation of alum adjuvant by NIH/Division of AIDS (DAIDS). The Bill & Melinda Gates Foundation provided funding for the study preparation and execution (INV-048573), as well as for the manufacturing of BG505 SOSIP.664 and 3M-052-AF.

By using additional opportunities to stimulate the immune system with the same study participants, IAVI will examine if a maturation of anti-HIV antibody response occurs following this boost immunization. The process of sequencing vaccine candidates to teach the immune system to produce broadly neutralizing antibodies to fight HIV is the approach of the overall germline targeting strategy in the field.