CytoDyn’s weekly injectable cloned antibody HIV treatment PRO 140 hit a key marker of success in a recent advanced trial of the therapy. The biotechnology company announced in a press release that a single injection reduced study participants’ viral load by half a power of 10 (68 percent).

The Phase IIb/III multicenter clinical trial enrolled 52 people living with HIV who had a viral load of at least 400, documentation of a detectable viral load at some point during the three months prior to their enrollment in the study, and resistance to antiretrovirals (ARVs) in three drug classes or to two classes of ARVs along with limited treatment options. The participants also all had what is known as CCR5-tropic virus, meaning their HIV attached to the CCR5 coreceptor on the surface of CD4 cells before infecting the cells instead of attaching to the CXCR4 coreceptor. PRO 140 works by preventing HIV from attaching to the CCR5 coreceptor.

The trial had an initial one-week, randomized, double-blind, placebo-controlled portion, during which all participants stayed on their existing ARVs, with one half of the study members randomized to receive an injection of PRO 140 and the other half randomized to receive an injection of a placebo.

After one week, those who received PRO 140, received a greater than half a power of 10 reduction in their viral load compared with those who received the placebo.

All participants will continue in the study and receive weekly injections of PRO 140 going forward.

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