Cost-Effectiveness of Sulbactam-durlobactam Compared with Colistin for Treating Carbapenem-Resistant Acinetobacter baumannii Infections in Critical Care Settings in the United States

Objective: Carbapenem-resistant Acinetobacter baumannii (CRAB) infections present a significant public health challenge in the United States due to multidrug resistance, substantial added inpatient costs, and subsequently high mortality rates. Method: A decision-analytic model was developed to evaluate the cost-effectiveness of sulbactam-durlobactam compared to colistin for treating CRAB infections, using data from the Acinetobacter Treatment Trial Against Colistin (ATTACK) trial, in which patients received either sulbactam-durlobactam or colistin alongside imipenem-cilastatin. The model incorporated survival rates, clinical outcomes (complete or incomplete cure), and the incidence and costs of acute kidney injury, which is more frequent in colistin-treated patients. Deterministic sensitivity analysis and two scenario analyses were performed. Results: The base case analysis estimated an expected per-patient cost of $57,887 for sulbactam-durlobactam compared to $55,157 for colistin. Patients treated with sulbactam-durlobactam had higher survival than those treated with colistin (0.66 versus 0.46), corresponding to 0.19 additional life saved per patient. The incremental cost-effectiveness ratio (ICER) for sulbactam-durlobactam compared with colistin was $14,097 per additional life saved. The ICER was most sensitive to the proportion of survivors with incomplete clinical cure for both treatments, the costs of sulbactam-durlobactam and cefiderocol, and survival outcomes in patients treated with sulbactam-durlobactam. Scenario analyses showed that the cost-effectiveness of sulbactam-durlobactam was sensitive to clinical cure outcomes, with ICERs ranging from $69,758 per additional life saved to dominance favoring sulbactam-durlobactam under different assumptions. Conclusions: Although treatment costs were higher, sulbactam-durlobactam has a favorable cost-effectiveness profile as compared with colistin when accounting for the costs of managing acute kidney injury.