Antibiotic Combo Shows Promise in Treating Urinary Tract Infections
Ceftolozane/tazobactam superior to levofloxacin in phase III trial (November 25)
Positive results have been reported from a pivotal study of the antibiotic candidate ceftolozane/tazobactam (Cubist Pharmaceuticals) in patients with complicated urinary tract infections (cUTIs). The combination treatment met its primary endpoint of statistical noninferiority compared with levofloxacin (10% noninferiority margin).
The double-blind, randomized, phase III trial compared the safety and efficacy of intravenous (IV) ceftolozane/tazobactam (1.5 g q8h) with that of IV levofloxacin (750 mg qd) in 1,050 adults with cUTI, including those in whom the infection had spread to the kidney (pyelonephritis). The trial’s primary endpoint was a composite of microbiological eradication and the clinical cure rate (composite cure rate) at 5 to 9 days after the end of therapy.
The 95% confidence interval (CI) around the treatment difference had lower and upper bounds of 2.3% and 14.6%, respectively, favoring ceftolozane/tazobactam.
Although this trial was not prospectively designed to demonstrate superiority, the finding that the lower bound of the 95% CI around the positive treatment differences in favor of ceftolozane/tazobactam was greater than zero indicated statistical superiority over levofloxacin.
Ceftolozane/tazobactam, an antibiotic candidate being developed to treat certain Gram-negative infections, consists of ceftolozane, a novel cephalosporin that has demonstrated more potent in vitro activity against Pseudomonas aeruginosa compared with currently available cephalosporins, with tazobactam, a well-established beta-lactamase inhibitor. The addition of tazobactam broadens coverage to include most extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae, and other Enterobacteriaceae.
Source: Cubist Pharmaceuticals; November 25, 2013.