Duration of Antifungal Therapy in Disseminated Coccidioidomycosis Patients: A Real-World Treatment Utilization Study

Background: Disseminated coccidioidomycosis (DCM) often requires prolonged antifungal therapy (AFT). Real-world data on AFT duration in DCM are limited. We evaluated time to AFT discontinuation among patients with DCM in the United States clinical practice. Methods: This retrospective, longitudinal study used STATinMED data (2016-2024). Patients had ≥1 International Classification of Diseases, Tenth Revision (ICD-10) code for DCM (B38.3, B38.4, B38.7, B38.81) during January 2017-December 2023, ≥1 claim for a triazole or amphotericin B within 21 days of the DCM diagnosis (index date), and continuous medical/pharmacy coverage during the 6-month baseline period. Discontinuation was defined as a ≥21-day gap without AFT. Antifungal agent/formulation switches were not considered discontinuations unless accompanied by a qualifying gap. The Kaplan-Meier methods were used to estimate time to discontinuation. Results: We identified 991 patients with DCM. Median age was 52 years (IQR 36, 65); 60.0% were men. Most resided in California (42.8%) or Arizona (33.6%). Initial AFT consisted predominantly of triazoles (96.8%), primarily fluconazole (83.2%). Discontinuation occurred in 27.6%, 40.0%, 54.2%, and 68.0% of patients by 3, 6, 12, and 36 months. Median AFT duration was 9.9 months. Conclusions: In a large US claims cohort, there was substantial variability in AFT duration in routine practice. Many patients had AFT durations under the lower limit of guideline recommendations for DCM, suggesting potential under-treatment, though appropriate clinical justifications may have existed.