Novel HIV Drug Candidate Highly Effective

Specialty Pharmacy Times, March/April 2015, Volume 6, Issue 2

In a study published online recently in Nature, researchers found an experimental drug candidate that is able to block every strain of HIV-1, HIV-2, and simian immunodeficiency virus isolated from either humans or rhesus macaques. The ability of the substance to block the virus includes the variants that are the hardest to stop, the study noted. The drug also protected against significantly higher doses of the virus than occur during most human transmission, offering this protection for at least 8 months following injection.

During HIV infection, the virus targets the CD4 lymphocyte and fuses with the cell before inserting genetic material that transforms the host cell into a viral manufacturing site. Previous studies have shown that the CCR5 co-receptor carries unusual modifications in the HIV-binding region, which allows proteins based on this region to be used in the prevention of infection.

For the study, the experimental drug was designed to simultaneously bind to 2 sites on the surface of the virus, which stops it from entering the host cell. The researchers designed a delivery vehicle that utilized existing technology to develop an engineered adeno-associated virus. This vehicle mimicked HIV in turning the cells into manufacturing sites able to produce enough of the protective protein to last for years, potentially even decades, according to the study.

“Our compound is the broadest and most potent entry inhibitor described so far,” Michael Farzan, lead researcher and professor at The Scripps Research Institute, said in a press release. “Unlike antibodies, which fail to neutralize a large fraction of HIV-1 strains, our protein has been effective against all strains tested, raising the possibility it could offer an effective HIV vaccine alternative.” SPT