CytoDyn’s injectable PRO 140 is proving to be an effective treatment for multidrug-resistant HIV, Healio reports.

Presenting their findings at the ASM Microbe conference in Atlanta, researchers conducted a study of the investigational humanized monoclonal antibody PRO 140 among 50 people who had HIV that was resistant to at least two antiretroviral (ARV) drug classes. All the participants were infected with HIV that is CCR5-tropic, meaning the virus attaches to the CCR5 coreceptor on the surface of CD4 cells (as opposed to the CXCR4 coreceptor). PRO 140 works by blocking HIV from binding to the CCR5 coreceptor.

During the first, one-week part of the study, the participants were randomized to receive one 350 milligram injection under the skin (subcutaneous) of PRO 140 or a placebo while continuing on their failing ARV regimen. During the second part of the study, the participants received weekly injections of the same dose of PRO 140 on an open-label basis (meaning they knew they were receiving the drug) for 24 weeks along with an ARV regimen that was optimized to be as effective as possible.

One week after receiving the single injection in the first part of the study, the participants’ average drop in viral load was 97 percent. The trial met the researchers’ preset goal of seeing a certain proportion of the participants experience at least a 0.5 log10 (about 32 percent) reduction in viral load at this point.

PRO 140 was generally well tolerated. None of the participants have experienced serious drug-related adverse health events, nor have any stopped treatment because of adverse health events.

Thirty-two people have finished the trial so far. Another 17 are still in the study and three dropped out early. Those who have completed 25 weeks of PRO 140 treatment have the option of continuing on the therapy.

To read a press release about the study, click here.

To read the Healio article, click here.