Return of the Antibodies: A Top HIV Clinical Development of 2016
|Top 10 Clinical Developments of 2016|
|1. Donald Trump||6. Return of the Antibodies|
|2. Switch Frenzy||7. Is an Unexpected Low HIV RNA Level Real?|
|3. 2-Drug ART||8. Dolutegravir and the Central Nervous System|
|4. Is HIV PrEP at a Tipping Point?||9. TAF in Hepatitis B|
|5. Start ART Now||10. New HIV infections in U.S. Are Down -- a Bit|
Not just aviator sunglasses, Ghostbusters and Brittney Spears are back; once again we are looking at antibodies to fight HIV infection. The idea harkens back to the earliest days of the epidemic when anti-HIV immunoglobulin therapy was tried but proved an epic fail. We now understand that typical antibody responses to HIV are insufficiently neutralizing against the virus to be useful. However, a small proportion of those infected produce unusual antibodies that are broadly neutralizing and can target not only the virus present in those persons, but even most virus strains found in others. Importantly, such broadly neutralizing antibodies (bNAb) can be synthesized and are being studied to treat and prevent HIV infection.
Last year, one bNAb, VRC01, was reported to decrease plasma HIV RNA levels in viremic patients. In 2016, two National Institutes of Health (NIH)-supported studies were presented that showed infusions of VRC01 in patients whose suppressive antiretroviral therapy (ART) was interrupted led to a more prolonged delay in viral rebound than expected based on data from other patients who had interrupted ART. Eventually, viral rebound did occur in those receiving the antibody, and a selection of virus that evaded the antibody was found. However, these studies provide the all-important proof-of-concept needed to light the fuse for future research initiatives. These include using bNAbs as adjuncts to ART and as agents to help reduce the latent reservoir and therefore facilitate eradication.
One of the more exciting areas of BNAb research is as a preventive intervention such as PrEP. The HIV Prevention Network Trial and HIV Vaccine Trials networks (NIH-funded) are conducting the AMP Study. In this trial, 2,700 men and transgender women at risk for HIV acquisition are randomized to two different doses of VRC01 or to a placebo infusion to determine the safety and protective afforded against HIV of the BNAb.
The Bottom Line
Immunotherapy is dawning as an important tool in the treatment of malignancies and has become first-line therapy for autoimmune conditions such as inflammatory bowel disease, psoriasis and rheumatoid arthritis. Infectious diseases such as hepatitis B and varicella have been treated with immunoglobulins as has, more recently, Ebola. Although many HIV providers may not yet be aware of bNAbs, it is likely they will be. Kinks need to be worked out, such as reducing production costs and developing an array of antibodies to avoid viral resistance, but these are not insurmountable. So, if asked what the next big thing is in HIV, just say, "bNAbs."
What are some other top clinical developments of 2016? Read more of Dr. Wohl's picks.
David Alain Wohl, M.D., is a professor in the Division of Infectious Diseases at the University of North Carolina at Chapel Hill, director of the North Carolina AIDS Training and Education Center and site leader of the University of North Carolina Chapel Hill AIDS Clinical Research Site.