Trius Therapeutics, Inc. has reached agreement with the FDA, under the Special Protocol Assessment (SPA) process, on the design of its planned Phase 3 study for the oral dosage form of torezolid phosphate for treatment of acute bacterial skin and skin structure infections (ABSSSI). The double-blind pivotal study will compare the efficacy and safety of once-daily oral administration of 200 milligrams of torezolid phosphate over six days of treatment to twice-daily oral administration of 600 milligrams of linezolid (Zyvox) for 10 days of treatment. The primary efficacy endpoint will be the cessation of spread of infected lesions and absence of fever at 48 to 72 hours following initiation of treatment.
Secondary endpoints will include, among other things, sustained clinical response at the end of therapy visit, and the investigator’s assessment of clinical response at all visits and clinical success at the post treatment evaluation visit. Provided non-inferiority is met, an assessment of superiority of torezolid phosphate to linezolid with respect to the primary efficacy endpoint will also be made.
Special Protocol Assessment
The SPA process creates a written agreement between the FDA and a sponsor concerning the clinical trial design, clinical endpoints and other clinical trial issues that can be used to support regulatory approval of a drug candidate. The process is intended to provide assurance that if the agreed upon clinical trial protocols are followed, the clinical trial endpoints are achieved and there is a favorable risk benefit profile, the data may serve as the primary basis of an efficacy claim in support of a New Drug Application (NDA).