Gilead Sciences Inc. said it has started human clinical trials onits anti-HIV drug.

The combined Phase I/II trials on GS393, or PMEA, are beingconducted at the National Institute for Allergy and InfectiousDiseases (NIAID), part of the National Institutes of Health inBethesda, Md.

GS393, a mononucleotide (an analog of adenine), acts inside thecell to interfere selectively with proteins essential for viralreplication. Published preclinical animal efficacy data havealready demonstrated that GS393 is more potent than AZT, theleading approved HIV anti-viral agent, in the simianimmunodeficiency virus monkey model for AIDS. In otheranimal studies, GS393 proved active against herpesvirus, whichcan cause severe infections in AIDS patients.

The Foster City, Calif., company (NASDAQ:GILD) filed theinvestigational new drug (IND) application for GS393 Sept. 28.

The company's stock closed down $1 a share on Friday to$15.50.

(c) 1997 American Health Consultants. All rights reserved.