In patients with lower urinary tract infections (UTI) or pyelonephritis, treatment with ceftolozane-tazobactam leads to better responses than high dose levofloxacin, according to the phase 3 ASPECT-cUTI trial.

Researchers randomly assigned 800 hospitalized inpatients with pyuria and a complicated lower UTI or pyelonephritis to receive either intravenous 1.5g ceftolozane-tazobactam every 8 hours or intravenous high-dose (750 mg) levofloxacin once daily for 7 days.

For the primary endpoint of a composite of microbiological eradication and clinical cure 5 to 9 days after treatment, investigators found ceftolozane-tazobactam was non-inferior to levofloxin, at 77% versus 68%.

Clinical superiority was also indicated for ceftolozane-tazobactam. Adverse event profiles were similar between the two groups and primarily nonserious.

Citation: Wagenlehner FM, Umeh O, Steenbergen J, Yuan G, Darouiche RO. Ceftolozane-tazobactam compared with levofloxacin in the treatment of complicated urinary-tract infections, including pyelonephritis: a randomised, double-blind, phase 3 trial (ASPECT-cUTI). Lancet. 2015. 385:1949-1956. doi: 10.1016/S0140-6736(14)62220-0.

Commentary: In some communities, up to 30% of e coli, the most common organism found in complicated urine infections, are resistant to levofloxacin. There is a paucity of new antibiotics as research has shifted more toward treatment of chronic diseases, and it is an important public health concern to have additional antibiotic choices with which to treat complicated infections. Ceftolozane-tazobactam (Zerbaxa, Cubist Pharmaceuticals) is a new antibiotic approved by the FDA in December 2014 for treatment of complicated intra-abdominal infections and complicated urinary tract infections. As shown in this study, it is more effective than levofloxacin in treating complicated urinary infections. —Neil Skolnik, MD