FDA Approves Orbactiv (Oritavancin) for Skin Infections
First single-dose antibiotic for Gram-positive infections
The FDA has approved Orbactiv (oritavancin, 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).
Orbactiv is the third antibacterial drug approved by the FDA this year to treat ABSSSIs. The agency gave the green light to Dalvance (dalbavancin, Durata Therapeutics) in May 2014 and to Sivextro (tedizolid, Cubist Pharmaceuticals) in June 2014. Orbactiv, however, is the only antibiotic approved to treat ABSSSIs with a single administration. Once fully infused over 3 hours, the treatment regimen is complete for patients with skin infections caused by susceptible Gram-positive pathogens.
The agency’s approval was based on the results of the randomized, double-blind SOLO I and SOLO II trials, which evaluated a single 1,200-mg intravenous (IV) dose of oritavancin for the treatment of ABSSSIs in 1,987 patients, and assessed 405 patients with documented MRSA infection. These studies demonstrated non-inferiority on the primary and secondary endpoints for 1,200-mg, once-only IV oritavancin dose infusion compared with 7 to 10 days of twice-daily vancomycin (1 g or 15 mg/kg).
The most common side effects identified in clinical studies included headache, nausea, vomiting, the formation of skin and soft-tissue abscesses on arms and legs, and diarrhea. The labeling for Orbactiv also includes a warning regarding interference with coagulation tests and interaction with warfarin.
Orbactiv (oritavancin) for injection is indicated for the treatment of adults with ABSSSIs caused by susceptible isolates of the following Gram-positive microorganisms: Staphylococcus aureus (including methicillin-susceptible and methicillin-resistant isolates), Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus anginosus group (including S. anginosus, S. intermedius, and S. constellatus), and Enterococcus faecalis (vancomycin-susceptible isolates only).
Patients with ABSSSIs often receive IV therapies that require hospital admission and multiple-day dosing. ABSSSIs are deep-tissue lesions (e.g., cellulitis, major cutaneous abscesses, and wound infections) and can be associated with significant co-morbidities, such as diabetes. A variety of pathogens may be identified in ABSSSIs, with two of the most common being S. aureus (methicillin-susceptible S. aureus and MRSA) and S. pyogenes.
Each year, more than 2 million Americans develop infections from antibiotic-resistant bacteria, according to the U.S. Centers for Disease Control and Prevention (CDC). One of the serious public health threats identified by the CDC is MRSA. Based on CDC data, approximately 80,000 severe MRSA infections and 11,000 deaths from MRSA occur in the U.S. each year.