O’Riordan W, et al. - As delafloxacin has been approved in the United States for acute bacterial skin and skin structure infections (ABSSSIs) caused by designated susceptible gram-positive and gram-negative organisms, researchers performed a comparison of the efficacy and safety of intravenous followed by oral delafloxacin with vancomycin plus aztreonam for the treatment of acute bacterial skin and skin structure infections. Outcomes suggest that intravenous (IV)/oral delafloxacin monotherapy was noninferior to IV vancomycin + aztreonam combination therapy for both the objective response and the investigator-assessed response at follow-up and late follow-up among patients with ABSSSI. The patients well tolerated delafloxacin as monotherapy.

Methods

• Researchers performed a multicenter, randomized, double-blind trial of 850 adults with ABSSSI.
• They compared delafloxacin 300 mg IV every 12 hours for 3 days with a switch to 450 mg oral delafloxacin, to vancomycin 15 mg/kg IV with aztreonam for 5–14 days.
• Objective response at 48–72 hours was assessed as the primary endpoint. Secondary endpoints included investigator-assessed response based on resolution of signs and symptoms at follow-up (day 14 ± 1), and late follow-up (day 21–28).

Results

• The intent-to-treat analysis set revealed the objective response of 83.7% in the delafloxacin arm and 80.6% in the comparator arm.
• The two arms were similar regarding investigator-assessed success at follow-up (87.2% vs 84.4%) and late follow-up (83.5% vs 82.2%).
• In eradication of MRSA, delafloxacin was comparable to vancomycin + aztreonam, at 96.0% vs 97.0% at follow-up.
• The groups were similar regarding frequency of treatment-emergent adverse events.
• The vancomycin + aztreonam group displayed higher treatment-emergent adverse events leading to study drug discontinuation (1.2% vs 2.4%).