Enrollment has begun in the 1st of 2 multinational clinical trials of an intravenously delivered investigational antibody for preventing HIV infection. Known as the AMP Studies, for antibody-mediated prevention, the trials will seek to determine whether giving people an investigational anti-HIV antibody called VRC01 as an intravenous infusion every 8 weeks is safe, tolerable and effective at preventing HIV infection. With a projected enrollment of 4,200 adults, the trials also are designed to answer fundamental scientific questions for the fields of HIV prevention and vaccine research. Precious studies done in the lab have shown that VRC01 stops up to 90% of HIV strains worldwide from infecting human cells, and is now considered to be a “broadly neutralizing antibody.”
“The AMP Studies could have a major impact on the future of HIV prevention and may be especially informative to HIV vaccine research,” said NIAID Director Anthony S. Fauci, M.D. “Many scientists believe that if a vaccine were developed that elicited broadly neutralizing antibodies in healthy people, it would protect them from HIV infection.”
In addition, researchers hope the AMP studies would be able to clarify what level of broadly neutralizing antibodies a vaccine or other long-acting HIV prevention method needs to achieve and maintain to provide sustained protection from the virus.
Although funded by The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), the AMP Study that just launched, HVTN 704/HPTN 085, will take place at 24 sites in Brazil, Peru and the United States, and will enroll 2,700 men and transgender people who have sex with men. The 2nd of the two AMP Studies, HVTN 703/HPTN 081, is planned to launch later this spring, enrolling 1,500 sexually active women at 15 locations in Botswana, Kenya, Malawi, Mozambique, South Africa, Tanzania and Zimbabwe. All study participants will be at high risk for the disease, but not already infected.
Participants will be assigned at random to receive an intravenous infusion of either VRC01 at a dose of 30 milligrams per kilogram (mg/kg), VRC01 at a dose of 10 mg/kg, or a saline solution (a placebo), for a total of 10 infusions, once every 8 weeks, and then will be followed for 20 more weeks. They will also be tested for HIV infection once every 4 weeks and at any time after reporting possible exposure to the virus. Results of the trials are expected in 2022.
Those who test positive for HIV will stop receiving infusions but will remain in the study for follow-up and will be referred to professionals in their communities for appropriate medical care. Meanwhile, everyone involved will receive the standard care for preventing HIV infection, including condoms and lubricant, counseling on how to reduce behaviors that increase risk for infection, and counseling and referral for antiretroviral to take immediately following suspected exposure to HIV (post-exposure prophylaxis).
In addition, volunteers in the AMP Studies will be referred to available local programs where they may obtain the oral medication Truvada to take daily for HIV prevention
“The immediate goal of antibody-mediated prevention of HIV is for each VRC01 infusion to have a protective effect that lasts for many weeks,” said Protocol Chair Myron Cohen, M.D. “Such a long-acting HIV prevention regimen might be easier for some people to follow than a daily regimen of oral medication, as currently required to prevent HIV infection.” Dr. Cohen is a principal investigator of the HPTN, associate vice chancellor for global health at the University of North Carolina at Chapel Hill and director of the university’s Institute for Global Health and Infectious Diseases.