Researchers have found a new broadly neutralizing antibody against HIV that has shown potency in neutralizing the virus in an early human trial.

This antibody, called 10-1074, targets a location on the virus’s shell known as the V3 loop. Two other promising antibodies under development, VRC01 and 3BNC117, go after a different point on the envelope of the virus (as the shell is known): the CD4 binding site. Because of these distinct points of attack, using the 10-1074 in combination with the other antibodies could put up barriers to viral resistance just as does combination antiretroviral (ARV) treatment, in which multiple drugs attack different phases in the viral life cycle.

Publishing their findings in Nature Medicine, researchers gave a single intravenous infusion of 10-1074 to 33 individuals, including 19 who had HIV and 14 who did not, and followed them for 24 weeks. Sixteen of the people with HIV were not on ARV treatment and had an average viral load of 12,851.

The antibody was well tolerated and had a half-life of 12.8 days in the HIV-positive participants and 24 days in the HIV-negative individuals.

Out of the 13 HIV-positive participants not on ARVs who received the highest dose of 10-1074 (30 milligrams per kilogram of body weight), 11 showed sensitivity to the antibody and a rapid decline in viral load, a 97 percent average drop.

The researchers looked for the emergence of viral resistance against the antibody in 15 of the 16 HIV-positive participants not taking ARVs. They found that multiple strains of 10-1074-resistant viruses emerged during the first few weeks after the infusion. Looking to determine whether such antibody resistance would affect the effectiveness of other broadly neutralizing antibodies, the scientists found that such resistance applied to the antibody PGT121, which also targets the V3 loop, but not to 3BNC117 and VRC01.

The researchers concluded that 10-1074 is safe and active against HIV and may be useful for treatment and prevention of the virus. They are planning further research to investigate these uses of the antibody.

To read the study abstract, click here.

To read a press release about the study, click here.