Editor's note: This story was updated on Aug 31 to include quotes from Brad Spellberg, MD.
The Food and Drug Administration (FDA) yesterday approved a new antibiotic combination drug for treatment of patients with complicated urinary tract infection (cUTI).
The drug, Vabomere, contains the antibiotic meropenem and the novel beta-lactamase inhibitor vaborbactam. Vabomere was developed to treat serious gram-negative infections, including cUTI, caused by carbapenem-resistant Enterobacteriaceae (CRE). CRE have been classified as an urgent health threat by the US Centers for Disease Control and Prevention and a priority pathogen by the World Health Organization.
The FDA said in a news release that Vabomere demonstrated statistical superiority over another antibiotic/beta-lactamase combination drug in a multi-center, randomized phase 3 clinical trial of 545 cUTI patients, including those with acute pyelonephritis (kidney infection). Phase 3 trials test the ultimate safety, efficacy, and dosage of drugs compared with the current gold standard treatment or placebo.
In the TANGO 1 trial, 98.4% of patients who received intravenous treatment with Vabomere had cure/improvement of symptoms and a negative urine culture test, compared with 94% of patients treated with piperacillin/tazobactam. Approximately 7 days after completing treatment, 77% of patients treated with Vabomere had resolved symptoms and negative urine culture, compared with 73% of patients treated with piperacillin/tazobactam.
Vabomere was also well-tolerated, with common adverse reactions including headache, infusion site reactions, and diarrhea.
In February, the FDA designated Vabomere as a qualified infectious disease product, which enabled the drug to receive a priority review from the agency. Priority review is a fast-track process for drugs that, if approved, would be a significant improvement in the treatment, diagnosis, or prevention of serious conditions when compared to standard treatments. The agency aims to take action on priority review drugs within 6 months, compared with 10 months for standard review.
A new weapon against CRE infections
Vabomere specifically addresses CRE such as Escherichia coli and Klebsiella pneumoniae by inhibiting the production of enzymes that block carbapenem antibiotics, one of the more powerful classes of drugs in the antibiotic arsenal. Bacteria that produce the K pneumoniae carbapenemase (KPC) enzyme are responsible for a large majority of CRE infections in the United States.
"With the dissemination of the KPC enzyme, new drugs that address this resistance mechanism to carbapenems are a welcome addition to our armamentarium," Cornelius Clancy, MD, chief of infectious diseases at the VA Pittsburgh Health System, said in a press release from The Medicines Company. Vabomere was developed by Rempex Pharmaceuticals, a unit of The Medicines Company.
"This is a big deal," Brad Spellberg, MD, an infectious disease specialist at University of Southern California, told CIDRAP News. "Meropenem-vaborbactam has broad-spectrum activity, including against serine carbapenemase-producing strains of CRE, such as KPC strains."
Spellberg added that Vabomere also improves coverage against worrisome pathogens like Pseudomonas aeruginosa and Acinetobacter baumanni compared to current treatments. "This is a needed drug," he said.
Vabomere is being evaluated against the best available therapy in another randomized phase 3 trial, TANGO 2, for treatment of patients with confirmed or suspected CRE infections of the blood, lung, urinary tract, and abdominal organs. In July, the company announced in a press release that randomization was being stopped early after interim data showed Vabomere demonstrated improved clinical cure rates across all infection types and reduced rate of renal adverse events.
A risk-benefit analysis of the data by the Data and Safety Monitoring Board determined that randomization of additional patients to the best available therapy group was no longer supported.
Aug 29 FDA press release
Aug 30 The Medicines Company press release
Jul 25 The Medicines Company press release