Gilead Sciences, Inc. has begun enrolling patients in a Phase I/II study of the company's oral HIV integrase inhibitor, GS 9137 (also known as JTK-303) for the treatment of HIV. This double-blind, randomized, placebo-controlled Phase I/II dose-escalation study will evaluate the tolerability, safety and antiviral activity of GS 9137 in HIV-positive patients.

GS 9137 is a novel HIV integrase inhibitor discovered by Japan Tobacco, Inc (JT) and licensed to Gilead in March 2005. The license granted Gilead exclusive rights to develop and commercialize GS 9137 in all countries of the world, excluding Japan where JT will retain rights. GS 9137 has been previously evaluated in a Phase I study in Japan to assess pharmacokinetics and safety in healthy volunteers.

Norbert Bischofberger, executive vice president, Research and Development, Gilead Sciences states, "HIV continues to be a major focus for Gilead, and integrase inhibitors represent a promising novel class of agents with the potential to inhibit HIV replication, particularly for patients whose HIV has developed resistance to other agents."