Authors: Martha Powell, Future Science Group
Results from an early-stage clinical trial, termed the APPROACH trial, have demonstrated the potential of an investigational HIV vaccine regimen, which was immunogenic and well-tolerated in healthy adults. In combination with results from the TRAVERSE trial, which are due later this year, these findings will inform the decision on whether to move forward with a larger trial to evaluate these vaccines’ safety and efficiency in women at risk of HIV.
In results presented at the 9th International AIDS Society Conference on HIV Science (23–26 July 2017, Paris, France) the team evaluated ‘mosaic’ vaccines, designed to induce an immune response against a variety of different HIV subtypes.
Pre-clinical trials were funded by the National Institute of Allergy and Infectious Diseases (NIAID, MD, USA) who, with the collaboration of partners, also supported the APPROACH trial. NIAID Director Anthony S. Fauci commented: “A safe and effective HIV vaccine would be a powerful tool to reduce new HIV infections worldwide and help bring about a durable end to the HIV/AIDS pandemic. By exploring multiple promising avenues of vaccine development research, we expand our opportunities to achieve these goals.”
The team assessed almost 400 volunteers across a variety of countries, including the United States, Uganda, Rwanda, South Africa and Thailand. All participants were randomly assigned to receive either one of seven experimental vaccine regimens or a placebo, and were administered four vaccinations over the course of 48 weeks.
The researchers discovered the different mosaic vaccine regimens were well-tolerated in these healthy participants and also and generated an immune response against HIV. Notably, the course that was reported to be most effective in pre-clinical animal studies also elicited the greatest immune responses in the study participants. However, the group state more research is needed as the ability to generate an immune response might not correlate with preventing HIV acquisition.
The researchers believe these findings support further evaluation of the lead vaccine regimen in a larger trial. If plans move ahead this is scheduled to begin enrollment in late 2017 or early 2018 in South Africa. The trial will aim to recruit 2600 healthy, HIV-negative women to further assess a regimen comprising two Ad26 mosaic primes and two boosters with Ad26 mosaic and clade C gp140.
Investigator, Dan H. Barouch (Beth Israel Deaconess Medical Center, MA, USA) concluded: “The promising, early-stage results from the APPROACH study support further evaluation of these candidate vaccines to assess their ability to protect those at risk of acquiring HIV.”