Two new studies published in the New England Journal of Medicine, suggest that immunotherapy could be used as an effective treatment – or functional cure – for HIV. According to the studies, immunotherapy could completely replace the daily medications taken by patients to manage their illness.
By injecting a broadly neutralizing HIV antibody (bNAb), known as VRC01, into patients with chronic HIV infections, the researchers found that the time to HIV viral rebound was moderately delayed. While the majority of patients saw viral suppression lasting eight weeks or less, the studies suggest that immunotherapy could eventually replace antiretroviral therapy for HIV suppression.
“I would compare these findings to early days of HIV treatment research in the late 1980s,” said Dr. Pablo Tebas, senior author of the study and director of the AIDS Clinical Trials Unit at the University of Pennsylvania. “In this study, we looked at one antibody, but we think it may take combinations of more potent antibodies to successfully control the virus.”
Early antiretroviral drugs were used as monotherapies to treat patients with chronic HIV infection. As the virus developed resistance to these agents, combination therapies were introduced to prolong viral suppression.
Current antiretroviral therapies are combination drugs taken once-daily, which improve patient outcomes but are unable to completely eradicate HIV from the system. Medication adherence to antiretroviral therapy can be difficult for some patients, and patients risk viral rebound if medication is not taken consistently.
Using bNab immunotherapy, HIV patients could receive an antibody injection in order to suppress the virus. Someday, this intervention could completely remove the need for those living with HIV to adhere to a daily antiretroviral therapy regimen.
“For the near future, it is unlikely that we will be able to fully eradicate HIV once a person has been infected. But a functional cure is a reasonable intermediate goal,” said Tebas. “The goal of immunotherapy is to eliminate the need to take a pill every single day while simultaneously chipping away at the latent reservoir of virus-infected cells. However, we are still years away from that goal. And even if a person is able to be functionally cured of HIV, long-term follow-up will be essential to ensure that the virus doesn’t return to high levels.”
While the patients participating in this immunotherapy trial did not see long-term virus control, the researchers determined that was likely due to pre-existing resistance to the therapy. For future studies, the researchers plan to determine whether more potent forms of immunotherapy could offer longer-last HIV suppression.