Antibody suppresses HIV for four months

A new antibody has shown potential as treatment for HIV with a mid-stage trial showing it suppressed the virus for up to four months after patients stopped taking antiretroviral medicines.

Developed by Taiwan’s United BioPharma and one of the US government-funded National Institutes of Health, the phase 2 study showed UB-421 was safe and did not induce production of antibody resistant HIV.

The study was supported in part by the US National Institute of Allergy and Infectious Diseases, and results were published in The New England of Medicine.

Conducted in Taiwan and led by United BioPharma’s chief scientific officer Chang Yi Wang, the study involved the 29 volunteers discontinuing their antiretroviral (ART) therapy at the time of their first infusion or a week later depending on their regimen.

Fourteen study participants received weekly injections of UB-421 over eight weeks while 15 received a higher dose biweekly for 16 weeks.

At the end of the eight- or 16-week treatment period, all volunteers restarted their previous ART regimen and were evaluated in follow-up visits up to eight weeks later.

Apart from a single participant who discontinued the study because of a mild skin rash, volunteers in both groups maintained HIV suppression (plasma HIV RNA levels under 20 copies/mL) throughout the treatment period in the absence of ART.

Including previous phase 1 and phase 2 studies, a total of 78 patients received the UB-421 treatment.

Previous studies using neutralising antibodies as a single have only suppressed HIV for a few weeks before the virus’ rapid mutation rate leads to development of resistant strains.

UB-421 avoids development of resistance by blocking the HIV binding sites on an unchanging human protein that HIV uses to infect T cells.

Further studies are planned in Taiwan and Thailand to test efficacy and safety of UB-421 as this study did not uses a comparator group receiving a placebo infusion.

In a related study, NIAID investigators currently are evaluating the safety of regular infusions of two highly potent broadly neutralising antibodies that may prevent the development of resistant HIV strains by targeting two distinct areas of the virus.