Phase I results of Tobira's TBR-652 CCR5 antagonist for the treatment of HIV

Tobira Therapeutics Inc., a clinical stage biotechnology company committed to research and product discovery for the treatment of life-threatening and life-altering infectious diseases, today announced pharmacokinetic data and results from a double-blind, placebo-controlled, multiple-dose randomized study of TBR-652 in sixty healthy volunteers. TBR-652, a CCR5 antagonist under investigation for the treatment of HIV, was evaluated at doses ranging from 25 mg once daily (QD) to 200 mg QD after a high fat meal. Pharmacokinetic parameters were measured on Days 1 and 10, while safety and tolerability were evaluated throughout the 10 day study. The results of the study demonstrate TBR-652 was well tolerated in all groups. TBR-652 reached maximum plasma exposure 3-6 hours post dose on Days 1 and 10. Mean plasma half-life ranged from 40 to 45 hours, supporting once daily dosing. Exposure pharmacokinetic measures were greater than the therapeutic level projected from in vitro studies of TBR-652.

"This Phase I study provides further clinical support for the continued development of TBR-652 in the treatment of HIV. We are very encouraged by the excellent exposure results from the study and look forward to results from ongoing trials," said James Sapirstein, CEO.

These data were presented at the 49th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), held September 12-15, 2009 in San Francisco, California. The poster presentation can be viewed at www.tobiratherapeutics.com.