FDA approves a new antibiotic to treat MRSA

FDA has approved antibacterial drug tedizolid phosphate (Sivextro, Cubist Pharmaceuticals) 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 the second new antibacterial drug approved by the FDA in the past month to treat ABSSSI. In May, dalbavancin (Dalvance, Durata Therapeutis) was approved for the treatment of adult patients with ABSSSI caused by susceptible Gram-positive bacteria, including MRSA.

Sivextro is a differentiated treatment that offers the potential to decrease hospital resource utilization, according to Steve Gilman, PhD, executive vice president, research & development and chief scientific officer of Cubist Pharmaceuticals.

It is available for intravenous and oral use. “As a once-daily, effective, short, 6-day course of therapy available in IV and oral formulation, Sivextro presents a strong value proposition,” he said.

Sivextro’s safety and efficacy were evaluated in 2 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.

Nausea, headache, diarrhea, vomiting and dizziness were the most common side effects identified in the clinical trials. 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.

Antibiotic resistance is not a problem that can be solved with the approval of 1 or 2 new antibiotics, according to Gilman. “It is an evolving issue and public health officials have outlined the need for new treatment options to address the problem,” he said.

According to the Centers for Disease Control and Prevention (CDC) “Antibiotic resistance threats in the United States, 2013” report, each year more than 2 million Americans become infected from bacteria that are resistant to antibiotics.

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 5 years of marketing exclusivity to be added to certain exclusivity periods already provided by the Food, Drug and Cosmetic Act.