Tobira Provides Results From In-Vitro TBR-652 Study

Tobira Therapeutics has revealed results from an in-vitro study evaluating TBR-652 in combination with lopinavir (LPV), darunavir (DRV), atazanavir (ATV), tenofovir (TDF), etravirine (ETV), and raltegravir (RAL), using the infectious replicative assay deCIPhR. Cytotoxicity was also assessed.

According to Tobira, the average 50% inhibitory concentration (IC50) for TBR-652 was 0.99+0.19nM. Weak synergy was seen in combinations of TBR-652 with LPV, ATV, DRV and ETV. Additive effects were seen with TBR-652 plus TDF or RAL. Importantly, no antagonism and no cytoxicity were observed with any 2-drug combination at any concentration tested.

James Sapirstein, CEO of Tobira, said: “These in-vitro results provide evidence that combination regimens containing TBR-652 and one or more of these agents are possible and should be further evaluated in HIV-infected patients.”

Reportedly, these data were presented at the 49th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), held in September 2009, in San Francisco.