Promising HIV vaccine trial discontinued

A promising clinical trial into a new HIV vaccine has been abandoned this week after it was found to be ineffective at preventing HIV.

The vaccine trial, known as HVTN 702, was being conducted by the HIV Vaccine Trials Network (HVTN) and sponsored by the National Institute of Allergy and Infectious Diseases (NIAID).

NIAID decided to call time on the trial after recommendations from the independent Data and Safety Monitoring Board (DSMB). Whilst the vaccine appears to have been safe it did prove ineffective at preventing HIV acquisition.

The hopes of the HIV vaccine field were high for HVTN 702, it was a modified version of the prime-boosting RV144 trial conducted in Thailand. Unfortunately these hopes didn’t become reality, but whilst this is disappointing there’s still much to be learnt from HVTN 702’s failure.

Linda-Gail Bekker, IAS Immediate Past President and Chair of the Enterprise Advisory Group said, “Whilst this is a significant setback for the field, we need to continue the quest for a preventive vaccine. The rates of HIV infection, which continue unabated in this region, should spur greater urgency, global attention and investment to the quest.”

The Enterprise applauds the HVTN for conducting an important study. “A well-conducted trial, even if efficacy is not observed, plays a critical role in informing HIV vaccine development,” said Roger Tatoud, Deputy Director of HIV Programmes and Advocacy at the IAS and who leads the work of the Enterprise. “We thank the trial volunteers, researchers and sponsors for their hard work and commitment. Other late-stage efficacy trials are continuing and these will be critical to add to our understanding of what an effective HIV vaccine strategy will be.”

Three other studies are currently being conducted investigating various prime-boost regimens. 

• Janssen Vaccines & Prevention B.V. is conducting HVTN 705 in 2,600 women in South-Africa and other sub-Saharan countries.
• Janssen Vaccines & Prevention B.V. are also testing a modified version of HVTN 705, called HVTN 706 which include gp140 mosaic, currently being trialled in 3,800 cisgender men and transgender individuals who have sex with other cisgender men and transgender men.
• The Antibody Mediated Prevention  programme is testing passive antibody administration as a prevention strategy in HVTN 703 and HVTN 704. These are proof-of-concept trials which attempt to harness broadly neutralising monoclonal antibodies (bNAbs) to prevent HIV. HVTN 703 is testing the regimen in women in seven countries in sub-Saharan Africa while HVTN 704 is being conducted with men who have sex with men and transgender people who have sex with men in the United States, Peru, Brazil and Switzerland.

“The effort, energy and resources that go into conducting trials of this size and complexity are extraordinary and the commitment of everyone involved is hugely appreciated. This level of passion, dedication and involvement will need to continue with renewed vigour as we move forward. We hope even more stakeholders will join the search for a preventive HIV vaccine,” said Anton Pozniak, IAS President.