US regulators have cleared Cubist Pharmaceuticals’ new antibiotic Zerbaxa (ceftolozane/tazobactam) to treat adults with complicated intra-abdominal infections and complicated urinary tract infections.

Zerbaxa, which consists of the cephalosporin antibiotic ceftolozane and the beta-lactamase inhibitor tazobactam, is the first new antibiotic approved in the US under the Generating Antibiotic Incentives Now (GAIN) Act to treat Gram-negative bacteria, and is the fourth new antibacterial agent approved in the country this year.

Complicated urinary tract infections (cUTI) and complicated intra-abdominal infections (cIAI) are a significant burden on the health system: UTIs are responsible for 30% of health-care acquired infections reported by hospitals, while cIAIs are among the most common infections in general surgery.

“The widespread prevalence of dangerous Gram-negative pathogens together with their increased resistance to existing antibiotics has created a serious public health threat,” said Louis Rice, Joukowsky Family Professor of Medicine and Chairman of the Department of Medicine at Warren Alpert Medical School of Brown University, who also sits on the Board of Directors of the Infectious Diseases Society of America, and he noted that Zebraxa “is a welcomed and much needed novel treatment”. 

Safety and efficacy were confirmed in two pivotal Phase III trials, which identified the most common side effects as nausea, diarrhoea, headache and fever. The drug’s label also includes a warning about decreased efficacy seen in patients with renal impairment. 

A decision from the European Commission on the drug is expected during the second half of 2015.