LAHORE: The global scientists have found encouraging results of latest Antibody Mediated Prevention (AMP) studies for HIV prevention, which show promise to prevent some HIV infections. The International AIDS Society (IAS) welcomed new results from two proof-of-concept AMP studies (HVTN 704/HPTN 085 and HVTN 703/HPTN 081) demonstrating that infusions of the broadly neutralising monoclonal HIV antibody (bNAb) VRC01 can prevent some HIV infections. The results of the AMP study, which were announced on Tuesday ahead of the opening of the 4th HIV Research for Prevention Conference (HIVR4P/Virtual), include data from more than 4,600 participants in two studies that enrolled HIV-negative men and transgender people who have sex with men in the US, Brazil and Peru (HVTN 704/HPTN 085) and HIV-negative cisgender women in sub-Saharan Africa (HVTN 703/HPTN 081).
The studies build off of traditional concepts of vaccination, in which a vaccine primes the immune system to make antibodies that can neutralise an infectious agent such as HIV. Instead of priming recipients to create antibodies, the AMP study infused participants with an antibody called VRC01, or a placebo, at eight-week intervals over 80 weeks.
With this approach, known as passive immunisation, AMP participants, who received the antibody, were 75 percent less likely to become infected with a strain of HIV that had been shown to be sensitive to VRC01 in in vitro studies. Importantly, however, the AMP studies also found that VRC01 was not protective against many strains of the virus. The study findings support the need for additional research on infusions with multiple antibodies capable of achieving broader protection against a variety of HIV strains.
“AMP is an exciting proof-of-concept study of a new and innovative potential form of HIV prevention,” said Adeeba Kamarulzaman, President of the IAS. “These studies open an important door to what may one day become yet another important approach to preventing HIV infection,” she said.
Roger Tatoud, Deputy Director of HIV Programmes and Advocacy at IAS and head of the IAS’s Global HIV Vaccine Enterprise, said that, like most innovative research studies, AMP produced complex results that also raise important new questions for researchers. “Moving forward, the field must consider the dual challenges of developing cocktails of antibodies that are both more broadly effective and more easily and practically delivered, while remaining affordable and accessible,” he added.
The AMP study investigators also explore implications for future development of passive immunisation approaches. During the upcoming HIVR4P // Virtual conference, the investigators will shed more light on presentation of the AMP results along with the latest research on antibody-mediated prevention, HIV vaccines, pre-exposure prophylaxis, treatment as prevention and new and emerging forms of prevention.
Susan Buchbinder, Chair of the IAS’s Global HIV Vaccine Enterprise Advisory Group, was of the view that AMP was a well-conducted study with excellent participant safety and retention. “We congratulate everyone involved, and in particular the study volunteers and team, who have made a vital contribution to HIV prevention research.”
With 1.7 million new HIV infections last year, she said, HIV remains an enormous global health crisis that requires multiple prevention options. “AMP demonstrates both the importance and the value of maintaining a strong, ongoing commitment to HIV prevention research,” she added.