NIAID Now | July 20, 2020
The National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, and IAVI, a nonprofit scientific research organization, recently announced a collaboration to develop combinations of HIV broadly neutralizing antibodies (bNAbs) that could be produced on a large scale at low cost to prevent and possibly treat HIV. This initiative also will leverage IAVI’s existing partnership with the Serum Institute of India Pvt. Ltd., a leading global producer of vaccines with a growing presence in monoclonal antibodies, to develop an affordable and globally accessible antibody-based HIV prevention product.
Many people living with HIV naturally produce bNAbs, which can stop a wide range of HIV strains from infecting human cells in the laboratory but arise too late after infection to effectively fight the virus. These antibodies are considered promising candidates for HIV prevention and treatment because they have few side effects and can last a long time in the body, suggesting that they could be dosed infrequently. Additionally, scientists can optimize known bNAbs by designing and engineering changes to increase the number of HIV strains an antibody can block, how long the antibody lasts in the body, how powerfully the antibody attaches to the virus, and how efficiently the antibody triggers the immune system to attack both the virus and HIV-infected cells.
Several bNAbs originally developed by scientists at NIAID’s Vaccine Research Center (VRC) are now being evaluated in NIAID-funded clinical trials for HIV prevention. The most advanced of these trials, the Antibody-Mediated Prevention (AMP) Studies, are testing whether giving HIV-negative people a bNAb called VRC01 as an intravenous infusion every 8 weeks is safe, tolerable, and effective at preventing HIV. The NIAID VRC discovered VRC01 in the blood of a person living with HIV in 2010 and subsequently manufactured the antibody for these trials. Results from the AMP Studies, expected later this year, will help direct future research that aims to harness the potential of bNAbs for HIV prevention.
New bNAbs that have been optimized in the laboratory are more potent and broad-acting than those being tested in ongoing clinical trials and potentially could be administered by subcutaneous injection rather than intravenous infusion. Under the new partnership, individual bNAbs identified and optimized by NIAID and by the IAVI Neutralizing Antibody Center at Scripps Research, made possible through long-term and continuing support from the President’s Emergency Plan for AIDS Relief (PEPFAR) through the United States Agency for International Development (USAID) to IAVI, will be combined and evaluated as combination bNAb products. NIAID will provide bNAbs optimized by NIAID scientists to IAVI, and together the partners will identify the best bNAb combinations to develop a product designed to protect against the wide variety of circulating HIV strains. Lead candidates identified through preclinical evaluation will be assessed in clinical trials to determine whether they can safely and effectively prevent HIV.
Notably, widespread implementation of a bNAb-based HIV prevention product, if proven safe and effective, would require that the product also be easy to manufacture on a large scale at low cost. IAVI and the Serum Institute will take the lead on developing manufacturing processes to accelerate the production of bNAbs for clinical research conducted in partnership with NIAID, and to lay the groundwork to help ensure that future HIV bNAb products will be affordable and globally accessible.
The initial focus of efforts by NIAID, IAVI, and the Serum Institute will be on developing combinations of bNAbs for HIV prevention, and the partners also may evaluate lead candidates as long-acting HIV treatments that would allow a person living with HIV to keep latent virus suppressed without daily medication. Clinical studies have established that giving infusions of certain individual bNAbs to people living with HIV can suppress the virus, albeit to a limited degree. Studies assessing whether combinations of multiple bNAbs can safely and more effectively suppress HIV are ongoing.