Janssen Vaccines & Prevention has announced results of a new study which points to a potential new approach against human immunodeficiency virus (HIV-1) infection.
The findings, published in Nature, suggest that combining therapeutic vaccination with immune stimulation could be a potential way to achieve a ‘functional cure’ for HIV infection. This strategy could suppress HIV infection long-term without the need for life-long antiretroviral therapy (ART).
The typical action of vaccines is to ‘teach’ the body to rid itself of viral invaders by provoking an immune response. HIV attacks cells of the immune system, killing the majority of infected immune cells but going dormant in others. This reservoir of dormant, infected cells, where researchers believe HIV remains hidden during ART, is the main reason why HIV cannot currently be cured.
In the new two-year study, conducted in non-human primates (NHPs) infected with simian immunodeficiency virus (SIV), a virus similar to HIV, the strategy was to draw the virus out of hiding with the goal of eradicating it from the body. Researchers combined two investigational therapeutic vaccines (an adenovirus serotype 26 vector vaccine (Ad26) and an MVA vector vaccine (MVA)) with a TLR7 agonist (an investigational drug that works on a protein of the immune system) into a treatment regimen to be administered alongside ART. When the treatment regimen was given to NHPs they achieved decreased levels of viral DNA in peripheral blood and lymph nodes, and improved viral suppression and delayed viral rebound when ART was stopped. The nine NHPs who received the investigational vaccine/TLR7 agonist combination showed decreased viral load, and the virus was undetectable in three of the NHPs when ART was stopped.
This provides an immunologic correlate which could potentially be used to predict responses in humans, but this needs to be confirmed in human clinical studies. Janssen, in collaboration with MHRP, recently began in-human studies to evaluate the potential of the HIV therapeutic vaccine in HIV infected patients who initiated ART during acute HIV infection.
Lead author Dan Barouch, Director of the Center for Virology and Vaccine Research at BIDMC and Professor of Medicine at Harvard Medical School, said: “The objective of our study was to identify a functional cure for HIV – not to eradicate the virus, but to control it without the need for ART. Current antiretroviral drugs, although they’re lifesaving, do not cure HIV. They merely hold it in check. We are trying to develop strategies to achieve ART-free, long-term viral suppression.”
Dr. Paul Stoffels, Chief Scientific Officer of Johnson and Johnson, said: “Our goal is to work across the entire continuum—to have a functional cure, which would keep patients’ virus under check without the life-long burden of being on treatments, and ultimately, to have a preventive vaccine that stops HIV in the first place.”
The study was conducted by scientists at Beth Israel Deaconess Medical Center (BIDMC), the United States Military HIV Research Program (MHRP) of the Walter Reed Army Institute of Research (WRAIR) and industry collaborators, including Janssen and Gilead Sciences.