Trius Therapeutics' Phase 1 trial establishes safety and tolerability of IV torezolid phosphate for MRSA

Trius Therapeutics, Inc. today announced results from its Phase 1 clinical trial evaluating the safety, tolerability and pharmacokinetics of the intravenous (IV) dosage form of torezolid phosphate, an IV and orally administered second generation oxazolidinone for the treatment of serious gram positive infections, including methicillin-resistant Staphylococcus aureus (MRSA).  The trial achieved its primary goal of establishing the safety and tolerability of the 200 mg IV dose of torezolid phosphate to be used in Trius' upcoming Phase 3 clinical trials. The study also demonstrated high oral bioavailability of torezolid phosphate. Trius believes that these results, coupled with data from the prior Phase 1 and Phase 2 clinical trials of the oral dosage form of torezolid phosphate, provide the clinical basis for Trius to proceed with its Phase 3 clinical trials planned for the second half of 2010.

In the single center trial, torezolid phosphate was tested in 75 healthy volunteers at single doses of 50, 100, 200 and 400 mg and at once-daily 200 or 300 mg doses for seven consecutive days. Separate arms of the trial examined the IV tolerability of the 200 mg dose, planned for Phase 3 clinical trials, and the oral bioavailability of torezolid phosphate. Consistent with pharmacokinetic data from the oral Phase 1 and Phase 2 clinical trials, this trial demonstrated that IV administered torezolid phosphate resulted in highly predictable exposure with little patient-to-patient variability and no accumulation after multiple daily doses. The 200 mg dose was safe and well tolerated for the seven days tested.  The oral bioavailability was determined to be approximately 92% when compared to IV dosing. These data indicate that no dose adjustment will be necessary for torezolid phosphate administered via either IV or oral routes, thus the same 200 mg dose may be used for both the company's planned oral and IV Phase 3 clinical trials.