Durata Therapeutics, Inc. (NASDAQ: DRTX) today announced preliminary, top-line results for its DISCOVER 1 ("Dalbavancin for Infections of the Skin COmpared to Vancomycin at an Early Response") Phase 3 study of dalbavancin, which is under investigation for the treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by susceptible gram-positive bacteria, including MRSA (methicillin resistant Staphylococcus aureus).
Preliminary top-line data show that dalbavancin achieved its primary endpoint of non-inferiority (10% non-inferiority margin) at 48-72 hours after initiation of therapy, as determined by the cessation of spread of the lesion, as well as the resolution of fever. Researchers were comparing two intravenous (IV) doses of dalbavancin given one week apart with twice-daily vancomycin doses for 14 days. Patients randomized to the vancomycin regimen had an option to switch to oral linezolid after three days of vancomycin treatment. In addition, the key secondary endpoints were supportive of the primary endpoint.
The DISCOVER 1 protocol was conducted pursuant to a special protocol agreement (SPA) with the U.S. Food and Drug Administration (FDA) based on the FDA's Draft Guidance for Developing Drugs for Treatment of ABSSSI. The protocol for the trial was also designed based on scientific advice provided by the European Medicines Agency (EMA). DISCOVER 1 was a randomized, double-blind, double-dummy trial conducted in 573 patients at 92 sites in the United States, Canada, and Europe comparing dalbavancin to a regimen of vancomycin and an option for oral linezolid for the treatment of ABSSSI.
ITT = Intent to Treat; CE = Clinically Evaluable
In the clinical trial, the treatment-related adverse event rate for dalbavancin was 12.3% and for vancomycin/linezolid was 18.3%. Adverse events reported in ≥ 3% of patients receiving dalbavancin in this trial were nausea, diarrhea, headache, and pruritus. Discontinuations due to treatment emergent adverse events were 1.8% and 2.1% for dalbavancin and vancomycin/linezolid, respectively. This adverse event profile is consistent with results from prior Phase 3 studies of dalbavancin. Further analyses, including the statistical analyses for the European regulatory submission, remain ongoing.