Prospective role of cefiderocol in the management of carbapenem-resistant Acinetobacter baumannii infections: Review of the evidence.

Carbapenem-resistant Acinetobacter baumannii (CRAB) has been classified by the World Health Organization as being in the critical category of pathogens requiring urgent new antibiotic treatment options. Cefiderocol, the first approved siderophore cephalosporin, was designed for the treatment of carbapenem-resistant Gram-negative pathogens, particularly the non-fermenting species A. baumannii and Pseudomonas aeruginosa. Cefiderocol is mostly stable against hydrolysis by serine β-lactamases and metallo-β-lactamases, which are leading causes of carbapenem resistance. This review collates the available evidence on the in vitro activity, pharmacokinetics/pharmacodynamics, and efficacy and safety of cefiderocol, and outlines its current role in the management of CRAB infections. In vitro surveillance data show susceptibility rates of >90% for cefiderocol against CRAB isolates as well as in vitro synergism with a variety of antibiotics recommended in guidelines. Clinical efficacy of cefiderocol monotherapy against CRAB infections has been demonstrated in the descriptive, open-label CREDIBLE-CR and the non-inferiority, double-blind APEKS-NP randomised clinical trials as well as in real-world cases in patients with underlying health problems. To date, the frequency of on-therapy development of cefiderocol resistance in A. baumannii appears to be low, but monitoring is highly recommended. Within current treatment guidelines for moderate-to-severe CRAB infections, cefiderocol is recommended for infections in which other antibiotics failed and in combination with other active antibiotics. In vivo pre-clinical data support the combination of sulbactam or avibactam with cefiderocol to enhance efficacy and to suppress the emergence of cefiderocol resistance. The benefit of combination therapy in the clinical setting is yet to be determined in prospective studies.