Top-line results from Durata Therapeutics’ dalbavancin Phase 3 study on ABSSSI

Dec 11 2012

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pursuant to a special protocol agreement (SPA) with the U.S. Food and Drug Administration (FDA) based on the FDA's Draft Guidance for Developing Drugs for Treatment of ABSSSI.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.

"We are very pleased with the preliminary results of this trial. There is a significant need for an innovative treatment option for patients suffering with ABSSSI. We anticipate results from our DISCOVER 2 study in the coming months and are proceeding toward submitting to the FDA a New Drug Application for dalbavancin in the first half of 2013," said Durata Chief Executive Officer Paul R. Edick.

"The development of new products, such as dalbavancin, makes this a very exciting time for patients and healthcare practitioners. Currently available IV treatment options for ABSSSI have limitations, including frequent dosing, antimicrobial resistance, and treatment-limiting adverse events. The potential opportunity to manage more patients more efficiently in ambulatory settings may well be an important advancement for providers of healthcare," said David Andrew Talan, MD, FACEP, FIDSA, Chairman, Department of Emergency Medicine and Faculty, Division of Infectious Diseases, Olive View-UCLA Medical Center.

"We believe there are approximately 35 million days of IV antibiotic treatment annually in the United States for patients with ABSSSI that are at risk for MRSA, with the majority of these treatments occurring in the hospital setting. Because therapy with dalbavancin would involve an initial dose followed by a second dose one week later, an alternative to hospital admission may become possible for many patients. This change in modality may help reduce the overall cost of treating ABSSSI to the healthcare provider while decreasing the potential spread of MRSA within the healthcare facility," said Durata Chief Medical Officer Michael Dunne, M.D.