The FDA has approved Sivextro (tedizolid phosphate), a new antibacterial drug, to treat adults with skin infections.

Sivextro is approved to treat patients with acute bacterial skin and skin structure infections (ABSSSI) caused by certain susceptible bacteria, including Staphylococcus aureus (including methicillin-resistant strains (MRSA) and methicillin-susceptible strains), various Streptococcus species and Enterococcus faecalis. Sivextro is available for intravenous and oral use.

Sivextro is the second new antibacterial drug approved by the FDA in the past month to treat ABSSSI. On May 23, the agency approved Dalvance (dalbavancin), also to treat patients with ABSSSI caused by Staphylococcus aureus and various Streptococcus species.

The application for Sivextro, intended to treat serious or life-threatening infections, was designated as a qualified infectious disease product (QIDP) and received an expedited review. Sivextro’s QIDP designation also qualifies it for an additional five years of marketing exclusivity to be added to certain exclusivity periods already provided by the Food, Drug and Cosmetic Act.

Sivextro’s safety and efficacy were evaluated in two clinical trials with 1,315 adults with ABSSSI. Participants were randomly assigned to receive Sivextro or linezolid, another antibacterial drug approved to treat ABSSSI. Results showed Sivextro was as effective as linezolid for the treatment of ABSSSI.

The most common side effects identified in the clinical trials were nausea, headache, diarrhea, vomiting and dizziness. The safety and efficacy of Sivextro have not been evaluated in patients with decreased levels of white blood cells (neutropenia), so alternative therapies should be considered.

Sivextro is marketed by Cubist Pharmaceuticals, based in Lexington, Mass.