Sulopenem or Ciprofloxacin for the Treatment of Uncomplicated Urinary Tract Infections in Women: A Phase 3, Randomized Trial

Background There are limited treatment options for uncomplicated urinary tract infection (uUTI) caused by resistant pathogens. Sulopenem etzadroxil/probenecid (sulopenem) is an oral thiopenem antibiotic active against multidrug-resistant pathogens that cause uUTIs. Methods Patients with uUTI were randomized to 5 days of sulopenem or 3 days of ciprofloxacin. The primary endpoint was overall success, defined as both clinical and microbiologic response at day 12. In patients with ciprofloxacin-nonsusceptible baseline pathogens, sulopenem was compared for superiority over ciprofloxacin; in patients with ciprofloxacin-susceptible pathogens, the agents were compared for noninferiority. Using prespecified hierarchical statistical testing, the primary endpoint was tested in the combined population if either superiority or noninferiority was declared in the nonsusceptible or susceptible population, respectively. Results In the nonsusceptible population, sulopenem was superior to ciprofloxacin, 62.6% vs 36.0% (difference, 26.6%; 95% confidence interval [CI], 15.1 to 7.4; P <.001). In the susceptible population, sulopenem was not noninferior to ciprofloxacin, 66.8% vs 78.6% (difference, -11.8%; 95% CI, -18.0 to 5.6). The difference was driven by a higher rate of asymptomatic bacteriuria (ASB) post-treatment in patients on sulopenem. In the combined analysis, sulopenem was noninferior to ciprofloxacin, 65.6% vs 67.9% (difference, -2.3%; 95% CI, -7.9 to 3.3). Diarrhea occurred more frequently with sulopenem (12.4% vs 2.5%). Conclusions Sulopenem was noninferior to ciprofloxacin in the treatment of uUTIs. Sulopenem was superior to ciprofloxacin in patients with uUTIs due to ciprofloxacin-nonsusceptible pathogens. Sulopenem was not noninferior in patients with ciprofloxacin-susceptible pathogens, driven largely by a lower rate of ASB in those who received ciprofloxacin. This phase 3, double-blind, double-dummy study comparing sulopenem to ciprofloxacin in women with uncomplicated urinary tract infections demonstrated comparable clinical response rates between treatment groups and antibiotic class dependent rates of post-treatment asymptomatic bacteria.