VimRx Pharmaceuticals Inc.'s antiviral hypericin completelyinactivates HIV when put into blood collected for transfusion.On Tuesday, the company announced results of studiesconducted at the New York Blood Center in which hypericininactivated more than five logs (more than 100,000 HIVparticles per milliliter of blood) of infectious HIV.

The data will be presented on Dec. 6 at the annual meeting ofthe American Society of Hematology. An abstract of the study,by Daniel Meruelo of New York University Medical Center et al,states that complete inactivation of HIV was obtained wheninfected blood was incubated with up to 40 uM of hypericin,illuminated for one hour with fluorescent light, and incubatedfor an additional three hours in the dark. In addition,researchers found that exposure of HIV-infected blood tohypericin for 24 hours in ordinary ambient light in the absenceof active illumination reduced the infective titers of HIV byabout four logs.

There were no adverse effects on stored red blood cells for upto 21 days. The authors concluded that "the apparenttransfusibility of hypericin, taken together with the efficacy ofthe virucidal activity and with the absence of adverse effectson stored red blood cells, may render hypericin useful forinactivation of infective viruses in red blood cell concentratesused for transfusion."

VimRx (NASDAQ:VMRX) of Stamford, Conn., noted that a smallpercentage of HIV-infected blood slips through currentscreening procedures, as there is a one-to-three month windowduring which newly-infected HIV-positive blood can testnegative.

Hypericin inactivates many other viruses, VimRx said,including cytomegalovirus, influenza and Epstein-Barr. VimRxpresident Richard Podell explained that the antiviral acts bytargeting free infectious virus before it invades a host cell andbegins to reproduce. Podell said the drug can also preventtransmission of the virus from an already infected cell to anuninfected cell. Hypericin goes into the membrane of the virus,activates oxygen, and binds together the viral proteins in thecore, preventing them from going out of the cell.

The National Institute of Allergy and Infectious Diseases hassponsored a Phase I study of intravenous hypericin in HIV-infected individuals and VimRx expects it to begin a Phase I/IIstudy with oral hypericin next month.

-- Brenda Sandburg News Editor

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