The National Institute of Allergy and Infectious Diseases (NIAID), has stopped administration of vaccinations in its HVTN 702 clinical trial of an investigational HIV vaccine.
This action was taken because an independent data and safety monitoring board (DSMB) found during an interim review that the regimen did not prevent HIV.
Importantly, the DSMB did not express any concern regarding participant safety.
The Phase 2b/3 study, named HVTN 702 or Uhambo, began in 2016 and is taking place in South Africa.
It was testing an investigational prime-boost vaccine regimen based on the only vaccine regimen ever to show protection from HIV—
“An HIV vaccine is essential to end the global pandemic, and we hoped this vaccine candidate would work. Regrettably, it does not,” said NIAID Director Anthony S. Fauci, M.D. “Research continues on other approaches to a safe and effective HIV vaccine, which I still believe can be achieved.”
The HVTN 702 study enrolled 5,407 HIV-negative volunteers at 14 sites across South Africa.
Study participants received six injections over 18 months, the safety of HVTN 702 study participants was closely monitored throughout the trial, and participants were offered the local standard of care for preventing HIV, including access to oral pre-exposure prophylaxis (PrEP).
In the January 23, 2020 interim analysis, the DSMB examined data from 2,694 volunteers who received the investigational vaccine regimen and 2,689 volunteers who received the placebo injection.
The analysis looked at how many participants were diagnosed with HIV after at least 60% of the participants had been in the study for more than 18 months — enough time for the vaccine regimen to stimulate an immune response.
In this analysis, 129 HIV infections occurred among the vaccine recipients, and 123 HIV infections occurred among the placebo recipients.
“We will continue to explore promising avenues for preventing HIV with other vaccines and tools, both in South Africa and around the world.” Said HVTN 702 Protocol Chair Glenda Gray, M.B.B.C.H., F.C.Paed. (SA).
There are many different strains of HIV and the vaccine had been adapted to the subtype most common is South Africa, which has one of the highest HIV rates in the world.
NIH is investing in multiple approaches to prevent HIV with the goal of delivering new options that are safe, effective, desirable to diverse populations, and scalable worldwide to help end the global pandemic.
These efforts include two other late-stage, multinational vaccine trials, Imbokodo and Mosaico, both testing a novel mosaic vaccine regime.
In addition, the proof-of-concept AMP trials are testing an intravenously delivered investigational antibody for preventing HIV.
Other cutting-edge studies, including the AMP trials, are investigating if broadly neutralizing antibodies (bNAbs) can protect against HIV.
Two other large-scale trials are testing an investigational long-acting injectable antiretroviral drug, cabotegravir, for HIV prevention.
Additional novel, long-acting HIV prevention products are also under study, including implants, vaginal rings, and combinations of bNAbs, and multi-purpose products that offer contraception along with HIV prevention.