According to the World Health Organization, Acinetobacter species top the list of critical bacterial pathogens that pose the greatest threat to human health, highlighting the high level of need for additional treatment options amid growing global resistance to antimicrobial medicines.

"The FDA is dedicated to supporting the development of safe and effective treatment options for infections caused by difficult-to-treat bacteria like Acinetobacter baumannii-calcoaceticus complex," said Peter Kim, M.D., M.S., director of the Division of Anti-Infectives in the FDA's Center for Drug Evaluation and Research. "Today's approval helps address a high unmet medical need by providing an additional treatment option for some of the sickest patients in our nation's hospitals."

Acinetobacter baumannii-calcoaceticus complex (henceforth referred to as A. baumannii) includes four species of bacteria in the Acinetobacter family. These bacteria can cause infections in various parts of the body, occurring most frequently in healthcare settings and predominantly causing pneumonia. A. baumannii can become highly resistant to multiple antibacterial drugs and current treatment options for drug-resistant A. baumannii are limited.  

Xacduro consists of sulbactam, a drug structurally related to penicillin, and durlobactam. Sulbactam kills A. baumanniiwhereas durlobactam protects sulbactam from being degraded by enzymes that may be produced by A. baumannii. Xacduro is administered by intravenous infusion.

Xacduro's efficacy was established in a multicenter, active-controlled, open-label (investigator-unblinded, assessor-blinded), non-inferiority clinical trial in 177 hospitalized adults with pneumonia caused by carbapenem-resistant A. baumannii. Patients received either Xacduro or colistin (a comparator antibiotic) for up to 14 days. Both treatment arms also received an additional antibiotic, imipenem/cilastatin, as background therapy for potential HABP/VABP pathogens other than Acinetobacter baumannii-calcoaceticus complex. The primary measure of efficacy was mortality from all causes within 28 days of treatment in patients with a confirmed infection with carbapenem-resistant A. baumannii. Of those who received Xacduro, 19% (12 of 63 patients) died, compared to 32% (20 of 62 patients) who received colistin; this demonstrated that Xacduro was noninferior to colistin.

The most common adverse reaction with Xacduro was liver function test abnormalities. Xacduro comes with certain warnings and precautions, such as hypersensitivity reactions and Clostridiodes difficile-associated diarrhea.

Patients should not receive Xacduro if they have a history of known severe hypersensitivity to components of Xacduro, sulbactam or other beta-lactam antibacterial drugs.

The FDA granted Xacduro Fast Track, Qualified Infectious Disease Product and Priority Review designations for this application.

The FDA granted the approval of Xacduro to Entasis Therapeutics.