B70-02 Safety and Tolerability of Isavuconazole in Patients With Chronic Pulmonary Aspergillosis

Abstract Background Isavuconazole (ISCZ) is a relatively new antifungal agent, and clinical reports on its safety and tolerability in chronic pulmonary aspergillosis (CPA) remain limited. This study aimed to evaluate the safety and tolerability of ISCZ with CPA. Methods We retrospectively reviewed the medical records of patients with CPA who received ISCZ at our institution between April 2024 and September 2025. Data collected included patient demographics, underlying diseases, prior antifungal therapy, reasons for ISCZ initiation (switch due to adverse events or first-line use), treatment duration, adverse events, and treatment continuation. Tolerability was evaluated based on the ability to continue therapy without discontinuation due to adverse events. Results Thirty-four patients were included (median age, 72.5 years interquartile range 70-79.25; 26 males 76.4%). The most common underlying disease was nontuberculous mycobacterial infection (n = 13), followed by chronic obstructive pulmonary disease (n = 10) and interstitial lung disease (n = 7). ISCZ was initiated due to adverse events from other antifungal agents in 22 patients (64.7%) and as first-line therapy in 12 patients (35.3%). Twenty-two patients (64.7%) were continuing therapy, and no serious adverse events were observed. The main adverse event was mild elevation of hepatic enzymes. Among these 22 patients continuing therapy, 14 of the 22 patients (63.6%) had already maintained treatment for more than 6 months. Furthermore, 14 of the 22 patients (63.6%) who switched from other antifungal agents and 8 of the 12 patients (66.7%) who received ISCZ as initial therapy were able to continue treatment. Among the 12 patients who discontinued ISCZ, 10 stopped due to adverse events, while 2 discontinued for other reasons. The adverse events leading to discontinuation were facial flushing (n = 3), hepatic dysfunction (n = 3), appetite loss or nausea (n = 2), drug-induced pneumonitis (n = 1), and febrile neutropenia (n = 1). The other two patients discontinued due to prioritization of treatment for Mycobacterium kansasii infection (n = 1) and difficulty swallowing the large 100 mg capsule (n = 1). Conclusion ISCZ demonstrated favorable tolerability in patients with CPA and was feasible both in those intolerant to other antifungal agents and in those receiving it as initial therapy. Although the efficacy of ISCZ was not directly evaluated in this study, the ability to maintain long-term therapy without serious adverse events is particularly meaningful in the management of chronic diseases such as CPA. ISCZ may therefore represent a valuable option for long-term treatment, especially in patients who are unable to tolerate other antifungal agents. This abstract is funded by: None