Safety and Efficacy of Ceftazidime–Avibactam in the Treatment of Children ≥3 Months to <18 Years With Complicated Urinary Tract Infection: Results from a Phase 2 Randomized, Controlled Trial

Background: Ceftazidime–avibactam is effective and well tolerated in adults with complicated urinary tract infection (cUTI), but has not been evaluated in children with cUTI. Methods: This single-blind, multicenter, active-controlled, phase 2 study (NCT02497781) randomized children ≥3 months to <18 years with cUTI (3:1) to receive intravenous (IV) ceftazidime–avibactam or cefepime for ≥72 hours, with subsequent optional oral switch. Total treatment duration was 7–14 days. Primary objective was assessment of safety. Secondary objectives included descriptive efficacy and pharmacokinetics. A blinded observer determined adverse event (AE) causality and clinical outcomes up to the late follow-up visit (20–36 days after the last dose of IV/oral therapy). Results: In total, 95 children received ≥1 dose of IV study drug (ceftazidime–avibactam, n = 67; cefepime, n = 28). The predominant baseline Gram-negative uropathogen was Escherichia coli (92.2%). AEs occurred in 53.7% and 53.6% patients in the ceftazidime–avibactam and cefepime groups, respectively. Serious AEs occurred in 11.9% (ceftazidime–avibactam) and 7.1% (cefepime) patients. One serious AE (ceftazidime–avibactam group) was considered drug related. In the microbiologic intent-to-treat analysis set, favorable clinical response rates >95% were observed for both groups at end-of-IV and remained 88.9% (ceftazidime–avibactam) and 82.6% (cefepime) at test-of-cure. Favorable per-patient microbiologic response at test-of-cure was 79.6% (ceftazidime–avibactam) and 60.9% (cefepime). Conclusions: Ceftazidime–avibactam was well tolerated in children with cUTI, with a safety profile consistent with that of adults with cUTI and of ceftazidime alone, and appeared effective in children with cUTI due to Gram-negative pathogens.