HIV antibody therapy looks promising
ANEW study of the effects of a new antibody treatment suggests it may offer a long-term solution for the control of HIV. There is no doubt that antiretroviral therapy (ART) for HIV has transformed what used to be a death sentence into a chronic condition, allowing infected people to live decades longer.
But ART has its drawbacks, not only in terms of physical side effects such as decreased bone density and kidney problems, but also in that stopping treatment or just missing a few doses causes the virus to resurge. The new study, published in the journal Science, concerns a different and potentially superior approach, in the form of a lasting immunotherapy that triggers an infected person’s immune system to make antibodies against HIV and clear it from the body.
Dr. Till Schoofs, one of the study’s first authors, and a researcher in molecular immunology at Rockefeller University in New York, NY, says: “This study provides evidence that a single dose of an antibody stimulates patients’ immune response, enabling them to make new or better antibodies against the virus.”
Last year, the team reported that the same treatment, based on a molecule called 3BNC117, can greatly reduce the amount of virus present in a patient’s blood. The new study reports the results of following the patients for a longer period of time to see how their immune systems are coping with the new therapy, explains Dr. Schoofs.
3BNC117 is called a broadly neutralizing antibody because it can fight more than 80 percent of the over 200 strains of HIV that infect people around the world. The molecule was isolated several years ago from a patient whose immune system showed exceptional ability in stopping the virus from infecting and killing CD4 immune cells, the destruction of which is a hallmark of AIDS.
For the phase I clinical trial, the researchers gave 15 patients with high blood levels of HIV a single injection of 3BNC117. Then, 6 months later, 14 of the patients were making new antibodies that were able to neutralize a number of different strains of HIV. Another group of untreated patients - whose HIV was controlled with ART - showed little change in their neutralizing activity over the same period, note the authors, who conclude that “3BNC117-mediated immunotherapy enhances host humoral immunity to HIV-1.”
HIV-1 is the predominant strain of HIV that causes the vast majority of global HIV infections. When people talk about HIV, they usually mean HIV-1. Dr. Schoofs suggests that since it usually takes years for the body to start making good antibodies against HIV, it could be that the effect of 3BNC117 increases with time, especially if the patient receives more than one dose.