FDA approves another antibiotic for hard-to-treat skin infections

FDA has approved oritavancin (Orbactiv, The Medicines Company) for injection for the treatment of adults with acute bacterial skin and skin structure infections (ABSSSIs) caused by susceptible designated Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA).

Oritavancin is the first and only antibiotic approved by FDA to treat ABSSSIs with a single, once-only administration. Once fully infused over 3 hours, the oritavancin treatment regimen is complete for patients with skin infections caused by susceptible Gram-positive pathogens.

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Oritavancin is the third new antibacterial drug approved by FDA this year to treat ABSSSI. The agency approved dalbavancin (Dalvance, Durata Therapeutics) in May 2014 and tedizolid (Sivextro, Cubist Pharmaceuticals) in June 2014.

It is also the third new drug designated as a Qualified Infectious Disease Product (QIDP) to receive FDA approval. “Under the Generating Antibiotic Incentives Now (GAIN) title of the FDA Safety and Innovation Act, oritavancin was granted QIDP designation because it is an antibacterial or antifungal human drug intended to treat a serious or life-threatening infection,” according to an FDA statement.

As part of its QIDP designation, the new drug qualifies for an additional five years of marketing exclusivity to be added to certain exclusivity periods already provided by the Food, Drug, and Cosmetic Act.

“The approval of Orbactiv adds another medication to the continuous growing arsenal of agents utilized in the treatment of ABSSSI,” said Clarence D. Moore, PharmD, BCSP, assistant professor, Howard University College of Pharmacy in Washington, D.C. “Orbactiv's unique single, once-only administration ensures that patients receive a complete treatment regimen without the burden of receiving multiple infusions for the management of ABSSSI. This attribute automatically improves patient compliance and potentially improves outcomes.”

The approval of oritavancin is based on the results of two clinical trials (SOLO I and SOLO II ), which were randomized, double-blind, multicenter studies that evaluated a single 1,200-mg IV dose of oritavancin for the treatment of 1,987 adults with ABSSSI, and assessed a large subset of patients with documented MRSA infection (405 patients). These trials demonstrated non-inferiority for the primary and secondary end points evaluating 1,200 mg once-only IV oritavancin dose infusion, versus 7 to 10 days of twice-daily vancomycin (1 g or 15 mg/kg).

Headache, nausea, vomiting, the formation of skin and soft tissue abscesses on arms and legs, and diarrhea were the most common side effects identified in the clinical trials. Oritavancin’s label also includes a warning regarding interference with coagulation tests and interaction with warfarin.