Cubist Pharmaceuticals has posted positive top-line results from the pivotal Phase III trial of its antibiotic candidate ceftolozane/tazobactam in complicated intra-abdominal infections (cIAI). The treatment, in combination with metronidazole, met the FDA- and EMA-defined primary endpoints of statistical non-inferiority compared to meropenem. The primary endpoint was a clinical cure rate 26 to 30 days after the initiation of therapy (the Test of Cure visit). For the FDA, the primary analysis was conducted in the Microbiological Intent-to-Treat (MITT) population; the non-inferiority margin was 10%; and the lower and upper bounds of the 95% confidence interval were -8.9% and 0.5%, respectively. For the EMA, the primary analysis population was Clinically Evaluable (CE) patients; the non-inferiority margin was 12.5%; and the lower and upper bounds of the 99% confidence interval were -4.2% and 4.3%, respectively. Results of the secondary analysis were consistent with and supportive of the primary outcome.

In the cIAI trial, the spectrum of pathogens seen was typical with that seen in other pivotal trials in patients with these types of complicated infections. The most common Gram-negative pathogens observed in this trial included Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae) and Pseudomonas aeruginosa (P. aeruginosa). The trial results follow the positive data reported last month from a Phase III trial of ceftolozane/tazobactam compared to levofloxacin in patients with complicated urinary tract infections (cUTI).

Cubist expects to submit an NDA to the FDA in 1H14. In 2H14, the Company plans to submit an MAA to the EMA.