IAVI statement on results from Mosaico HIV vaccine trial

Pharmaceutical company Johnson & Johnson announced on January 18 the discontinuation of a Phase III HIV vaccine clinical trial known as Mosaico (HVTN 706/HPX3002), sponsored by Janssen Vaccines & Prevention B.V., part of the Janssen Pharmaceutical Companies of Johnson & Johnson. The trials Data Safety Monitoring Board evaluated interim data and made the recommendation to stop the trial based on lack of an efficacy signal. Importantly, no safety issues with the vaccine regimen were identified.

“IAVI would like to recognize Janssen, the study investigators, and the volunteers for their tremendous commitment to and impressive collaboration in conducting this large and complex efficacy trial,” said Mark Feinberg, M.D., Ph.D., president and CEO of IAVI. “A safe, effective, broadly accessible HIV vaccine remains an urgent global health priority. Going forward, IAVI and our collaborators believe that the most promising new HIV vaccine approaches are those intended to induce broadly neutralizing antibodies, and we are encouraged by recent scientific progress toward that goal.”

The “holy grail” of HIV vaccine research is a vaccine that induces broadly neutralizing antibodies, or bnAbs, to block HIV’s many strains. Recently, scientists with Scripps Research, IAVI, Fred Hutchinson Cancer Center and the National Institute of Allergy and Infectious Diseases Vaccine Research Center at the National Institutes of Health published promising study data from a first-in-human clinical trial of a novel HIV vaccine design strategy. The data reveal that the vaccination strategy successfully primed the immune system as the first stage in the production of bnAbs using an engineered immunogen. IAVI, Scripps Research, the Bill & Melinda Gates Foundation, Moderna, and other partners have subsequently launched further trials of this candidate. In addition, recent findings of the antibody mediated prevention trial confirm that developing vaccine candidates to elicit bnAbs is a viable strategy that could lead to protection.

The vaccine regimen tested in Mosaico was based on “mosaic” immunogens — vaccine components designed to induce non-neutralizing immune responses against a wide variety of global HIV strains. The study included approximately 3,900 cisgender men and transgender people who have sex with cisgender men and/or transgender people at high risk of acquiring HIV in Europe and the Americas. A previous Phase IIb trial evaluating the same investigational vaccine [Imbokodo (HVTN 705/HPX2008)] in cisgender women in sub-Saharan Africa was halted for lack of efficacy in 2021.

Analysis of the Mosaico data will continue. For more information on the vaccine regimen tested in Mosaico and the study design, visit the study website.