Complicated urinary tract infections:
A multinational, double-blind study enrolled 1,068 adults hospitalized with cUTI (including pyelonephritis) who were randomized to Zerbaxa (ceftolozane/tazobactam 1 g/0.5 g intravenously every 8 hours) or levofloxacin (750 mg intravenously once daily) for 7 days of therapy. The primary efficacy endpoint was defined as complete resolution or marked improvement of the clinical symptoms and microbiological eradication. The primary efficacy analysis population was the microbiologically modified intent-to-treat (mMITT) population, which included all patients who received study medication and had at least 1 baseline uropathogen. The mMITT population consisted of 800 patients with cUTI, including 656 (82%) with pyelonephritis. Zerbaxa demonstrated efficacy with regard to the composite endpoint of microbiological and clinical cure at the TOC visit in both the mMITT and ME populations. In the mMITT population, the composite cure rate in Zerbaxa-treated patients with concurrent bacteremia at baseline was 23/29 (79.3%). Although a statistically significant difference was observed in the Zerbaxa arm compared to the levofloxacin arm with respect to the primary endpoint, it was likely attributable to the 212/800 (26.5%) patients with baseline organisms non-susceptible to levofloxacin. Among patients infected with a levofloxacin-susceptible organism at baseline, the response rates were similar.