Real-Life Cefiderocol Use in Bone and Joint Infection: A French National Cohort.

Background: Cefiderocol (CFD) is a novel siderophore cephalosporin developed for the treatment of infections involving multidrug-resistant (MDR) Gram-negative bacilli (GNB) infections (1-3). For bone and joint infections (BJIs), the use of CFD is currently neither part of its market authorization nor recommended, and has not yet been assessed by large-scale studies. Objectives: To fill the scarcity of data regarding the use of CFD in BJIs, we aimed to describe patients' and infection characteristics along with the outcomes of the infection. Methods: We conducted a retrospective observational multicenter study in 22 French centers from January 2019 to December 2023. Results: From January 2019 to December 2023, 45 patients were included. Patients were mainly males (73%) with a median age of 62 years (interquartile range [IQR] 29), and a median Charlson comorbidity index of 3. Implant-related infections (20) were the most prominent, accounting for 44% of the cases. Carbapenemase-producing GNB were involved in 74% of the cases (n = 17/23), among which Pseudomonas aeruginosa accounted for 38% of these cases. Most patients received 6 g of CFD per day. CFD was used in combination with an antibiotic in 40 out of 45 cases (89%). The median duration of CFD treatment was 34 days. Seven patients (16%) experienced side effects, mainly gastro-intestinal disorders, including three (7%) who induced treatment cessation. Infection control included surgery in 37 (82%) patients. Failures and deaths occurred, respectively, in 22 (49%) and 10 (22%) cases. Conclusions: Our results suggest that CFD may be an alternative in MDR-GNB infections with limited therapeutic options.