CytoDyn is a biotech company that specialise in the development of new therapies to combat HIV infection. They announced yesterday that they have concluded a phase 2B study of PRO 140, a treatment substitution therapy for people with HIV. The exciting news is that 98% of the patients maintained undetectable viral load after 4 weeks of monotherapy with PRO 140.

As the initial results were so good, they have had a few patients successfully continue with the treatment for as long as 6 months with no viral load rebound.The basic idea behind PRO 140 is to try and give people a break from their HAART ( Highly Active Antiretroviral Therapy), which can have side effects and requires taking medication daily, by giving them weekly injections with PRO 140. In the study 98% of patients successfully passed 4 weeks of monotherapy, 91% passed 6 weeks, 82% 8 weeks , 70% 11 weeks and 14 patients are approaching 6 months, with no viral rebound. The therapy as also been proven to be safe with no major adverse events or safety concerns.

PRO 140 is a viral entry inhibitor, an entirely new class of HIV therapeutics . The idea is that it can prevent healthy cells from being infected with HIV in the first place. PRO 140 is a fully humanised monoclonal antibody specifically directed against CCR5, one of the receptors HIV attaches to, to infect cells . It is designed to attach to this receptor and therefore keep HIV from entering the cells that way . The good news is that the PRO 140 doesn’t appear to interfere with the normal function of CCR5. So far PRO 140 has had 7 studies and it appears to be safe and well tolerated with the benefit of keeping viral load under control, with less frequent dosing and less side effect than current therapies that are in use.

PRO 140 has been designated fast track status by the FDA and the company is awaiting further guidance from the FDA as to how to proceed with further trails in this exciting new emerging therapeutic

Future studies will now be undertaken to establish whether it may be possible for people to have treatment interruptions from their current HAART, with the potential to reduce daily pill burden, side effects and costs.

It’s obviously still early days but very exciting news indeed.