No Difference in Adverse Events Between Delafloxacin or Vancomycin/Aztreonam in ABSSSI

FDA Approves Baxdela
FDA Approves Baxdela
Incidence of adverse events with delafloxacin (Baxdela™, Melinta Therapeutics) was comparable to the combination regimen of vancomycin plus aztreonam across 2 phase 3 registrational ABSSSI studies.
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SAN DIEGO – Delafloxacin (Baxdela™, Melinta Therapeutics), had similar adverse event (AE) profiles when compared with vancomycin/aztreonam as treatment options in patients with acute bacterial skin and skin structure infection (ABSSSI), according to findings from 2 multicenter double-blind, randomized phase 3 trials presented at IDWeek 2017.

Investigators evaluated outcomes in patients with ABSSSI who received delafloxacin 300 mg IV every 12 hours, or delafloxacin 300 mg IV every 12 hours for 3 days with a mandatory blinded switch to oral delafloxacin 450 mg every 12 hours, or vancomycin 15 mg/kg IV (actual body weight) with aztreonam between 5 to 14 days. AEs reported at baseline to 30 days following the final drug dose contributed to the safety data. Investigators were blinded when reporting all AEs.

A total of 1492 patients with ABSSSI received a minimum of 1 treatment dose. Baseline patient characteristics included obesity (42%), the presence of diabetes (11%), and renal impairment (16%). The rates of AEs were similar in the two groups. Overall, gastrointestinal AEs were the most common: 17% in the delafloxacin group vs 13% in the vancomycin/aztreonam group. Discontinuation of therapy due to AEs was observed in <1% of patients treated with delafloxacin.

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In the delafloxacin and vancomycin/aztreonam groups, 1.1% and 1.7%, respectively, had alanine transaminase >5 times the upper limit of normal. One patient with a prior history of Bactrim/clindamycin therapy had a C difficile infection on delafloxacin. In comparison with vancomycin/aztreonam, no increase in fluoroquinolone-associated events was observed in the delafloxacin patients. In addition, researchers found no incidences of symptoms consistent with fluoroquinolone-associated disability.

“The safety data for delafloxacin are very encouraging. Safety is particularly important for the fluoroquinolone class of antibacterials because of unexpected toxicities of earlier members of the class. New fluoroquinolones, like delafloxacin, are now specifically screened carefully for the adverse effects seen with some of the earlier agents, and the results with delafloxacin are quite promising,” concluded David Hooper, MD, from Massachusetts General Hospital, in an interview with Infectious Disease Advisor.


Sue K. Cammarata, MD, is the chief medical officer of Melinta Therapeutics, Inc. All other authors have received consulting fees from Melinta Therapeutics, Inc.

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Corey GR, Hooper D, Lodise Jr TP, Tseng C, Cammarata SK. Comparison of safety profile of delafloxacin (DLX) versus vancomycin/aztreonam (VAN/AZ) in thetreatment of patients (pts) with acute bacterial skin and skin structure infections (ABSSSI): integrated safety findings from two phase III studies. Presented at: IDWeek 2017; October 4-8, 2017; San Diego, California; Poster 1858.