Antibacterial Drug Label Gets a Facelift One Year After FDA Approval

The antibacterial drug Avycaz (ceftazidime-avibactam) was given priority review by the Food and Drug Administration (FDA) since new safety data has been discovered.

Avycaz was approved to treat complicated intra-abdominal infections (cIAI) in February 2015. Exactly one year later (minus one day), the label needs a facelift since results have come in from two Phase 3 trials — the original label was based off of Phase 2 data including in vitro analysis. The current label says that Avycaz should be used for patients with cIAI and cUTI who have limited or no other treatment options.

The medication treats cIAIs, including pyelonephritis caused by bacteria like Enterobacteriaceae and Pseudomonas aeruginosa. The two Phase 3 studies evaluated safety and efficacy of Avycaz in combination with metronidazole. Some of the patients had infections due to Gram-negative pathogens that were considered resistant to ceftazidime on its own, but susceptible to Avycaz.

“In these studies, clinical cure rates at the Test of Cure (TOC) time point met the primary endpoint of statistical non-inferiority to meropenem,” according to a news release from pharmaceutical company Allergan.

The drug was active in vitro against Pseudomonas aeruginosa when in the presence of some AmpC beta-lactamases and certain strains that were lacking the outer membrane porin (OprD). In addition, Avycaz worked in vitro against Enterobacteriaceae when it was in the presence of beta-lactamases and extended-spectrum beta-lactamases (ESBLs) of these groups:

• TEM
• SHV
• CTX-M
• Klebsiella pneumoniae carbapenemase (KPCs)
• AmpC
• Certain oxacillinases (OXA)

The report specified that Avycaz does not work on bacteria that produce metallo-beta lactamases and it may not be active against Gram-negative bacteria that overexpress efflux pumps or have porin mutations.

These results have moved Avycaz into priority review for the FDA.

“This acceptance is encouraging, as the inclusion of full Phase 3 clinical data to the label further demonstrates the safety and efficacy of Avycaz in difficult-to-treat infections and provides physicians further validation of the drug’s spectrum of activity against pathogens of greatest concern,” said David Nicholson, PhD, president and executive vice president of Global R&D at Allergan.