An experimental treatment has been developed, which put SIV, the simian form of HIV, into remission and kept it suppressed for 23 months after the treatment was completed, researchers in the US said last Thursday. Additionally, the treatment restored immune cells destroyed by the virus, a process unachievable with antiretroviral therapy (ART) alone. The findings were published October 13, in the journal Science.
"Our data suggest that the immune systems of these animals are controlling SIV replication in the absence of antiretroviral therapy," said Anthony S. Fauci, MD, who co-led the study as chief of the Laboratory of Immunoregulation at the National Institute of Allergy and Infectious Diseases (NIAID), part of NIH.
"The experimental treatment regimen appears to have given the immune systems of the monkeys the necessary boost to put the virus into sustained remission. The precise mechanisms of this effect are unclear and will be actively pursued since they could have important implications for the control of HIV infection in humans in the absence of ART. At this point it is also unclear whether the findings of the newly reported animal study will translate into a clinical benefit for HIV-infected people," he stated.
The experimental treatment consisted of 90 days of traditional ART, together with 23 weeks of a laboratory-derived monkey antibody, similar to the human drug vedolizumab, which is used for treating ulcerative colitis and Crohn's disease.
"The new findings suggest an alternative form of HIV therapy that may eliminate a requirement for lifelong daily ART, potentially improving the quality of life for people living with the virus and reducing the staggering, unmet cost of antiretroviral therapy for the 37 million people worldwide who need it," said Aftab A. Ansari, Ph.D., senior author of the paper and co-leader of the study.
The researchers are hopeful to learn how the antibody works, so as to model an effective vaccine. They question whether the treatment, using vedolizumab combined with ART, would cause a suppression of the virus over the long term.
It is reported that the new treatment is being tested in HIV-infected people at the NIH Clinical Research Center in Bethesda, Maryland, as part of a small, early-phase clinical trial.