Real-World Clinical Outcomes of Sulbactam-Durlobactam Against Carbapenem-Resistant Acinetobacter baumannii with Diverse β-Lactamase Profiles: A Multicenter Study in China.

BACKGROUND

Sulbactam-durlobactam (SUL-DUR) was approved in China in 2024 for the treatment of carbapenem-resistant Acinetobacter baumannii (CRAB) infections. However, real-world clinical data-particularly in critically ill patients and against isolates harboring diverse β-lactamases-are limited.

METHODS

We conducted a multicenter, retrospective case series across three hospitals in Hubei Province, China (January 2025 - March 2026), to evaluate the clinical efficacy, safety, and preliminary pharmacoeconomic profiles of SUL-DUR in patients with CRAB infections.

RESULTS

Twenty-one patients were included; SUL-DUR was administered as primary (n=12) or salvage (n=9) therapy. Infections primarily involved the respiratory tract (n=20) and bloodstream (n=3). Genetic profiling of available isolates (n=18) identified OXA-23 (94.4%) as the predominant β-lactamase, alongside the co-production of KPC and ESBLs in a subset of strains. Despite critical illness-with 38.1% of patients requiring continuous renal replacement therapy (CRRT) and 14.3% requiring extracorporeal membrane oxygenation (ECMO)-the overall clinical improvement rate was 57.1%. Notably, both patients receiving SUL-DUR as salvage therapy for bacteremia survived. Mild, reversible renal or hepatic laboratory abnormalities occurred in 28.6% of cases. Pharmacoeconomic analysis indicated that although SUL-DUR carries a higher defined daily cost, patients achieving clinical improvement had a shorter median length of stay and lower total daily treatment costs compared to those experiencing clinical failure.

CONCLUSION

SUL-DUR, administered exclusively as part of combination regimens, was associated with favorable clinical outcomes and a manageable short-term safety profile in this small cohort, including in patients requiring extracorporeal life support and those infected with strains co-harboring multiple β-lactamases. These descriptive findings are hypothesis-generating and, given the small sample size, the absence of a comparator group, and the use of combination therapy in all patients, should be interpreted with caution; any apparent pharmacoeconomic advantage associated with early clinical improvement requires confirmation in controlled studies.