Targanta reports promising in vivo data from C difficile infection study

In the study, oritavancin activity at 10, 50 and 100mg/kg/day and a pegylated (PEG400) formulation of oritavancin at 100mg/kg/day were compared to vancomycin activity at 50mg/kg/day against clindamycin-induced Clostridium difficile (C difficile) infection in Golden Syrian hamsters.

Results showed that all doses of oritavancin were highly effective in prolonging survival compared to untreated controls, and prevented relapse longer than treatment with vancomycin at equivalent dose.

Oritavancin at 100mg/kg exhibited superior efficacy to vancomycin at day 12: 100% survival was observed for animals treated with oritavancin compared to 0% survival with vancomycin. The PEG400 formulation of oritavancin protected all hamsters from relapsing, yielding 100% survival out to day 20, compared to vancomycin (0% survival).

These data are said to be consistent with previously presented results from in vitro gut model studies demonstrating that, while both oritavancin and vancomycin were effective in treating clindamycin-induced C difficile infection, only oritavancin appeared active against the spore forms of the bacteria, suggesting that oritavancin may prevent recurrence of disease.

Targanta plans to continue advancing this program and initiating additional studies that would possibly enable the testing of orally-administered oritavancin for the treatment of C difficile in the first half of 2009.