Peregrine says study shows anti-HIV potential of antibodies

Peregrine Pharmaceuticals Inc. announced April 5 the publication of data showing phosphatidylserine (PS)-targeting antibodies can block one of the key ways the AIDS virus gains entry into certain blood cells.

Scientists at Duke University generated the data as part of their ongoing AIDS vaccine research. Their article is available online and will be published in the April 12 edition of the Journal of Experimental Medicine.

Peregrine's PS-targeting antibodies are in clinical development for the treatment of cancer and HCV infections, the company stated in its press release.

In early stage in vitro studies reported by Dr. Anthony Moody of Duke, PS-targeting antibodies developed or licensed by Peregrine blocked HIV from docking with its most commonly used entry point into blood cells — the CCR5 receptor. The antibodies accomplished this indirectly, by binding to white blood cells and causing them to secrete proteins that have the ability to block entry of HIV into the cell. In the presence of monocytes, the antibodies prevented HIV infection in vitro 85 percent of the time in these studies.

Investigators believe the finding has particular strategic importance because most HIV strains use the CCR5 receptor to gain entry into a cell. In addition, it is one of the earliest events in the process of infection; so being able to intervene at this juncture could potentially be clinically useful.

 "These results indicate that targeting a host cell lipid such as PS as an anti-viral strategy is a promising concept of relevance to new therapeutic and possibly prophylactic innovations for HIV," said Barton Haynes, director of the Duke Human Vaccine Institute and senior author of the study.

The study was supported by a Collaboration for AIDS Vaccine Discovery grant from the Bill and Melinda Gates Foundation, a Veterans Affairs Merit Review Award, an NIAID NIH grant, the Center for HIV/AIDS Vaccine Immunology as well as resources from the University of Alabama and the Birmingham Center for AIDS Research.