Real-World Effectiveness and Safety of Isavuconazole Versus Amphotericin B for Patients with Invasive Mucormycosis

Background: Invasive mucormycosis (IM) poses a substantial morbidity and mortality burden among immunocompromised patients. Objectives: We aim to compare the real-world effectiveness and safety of isavuconazole with those of amphotericin B in patients with IM. Patients and methods: In this observational cohort study, we enrolled patients who were diagnosed with IM and treated with either isavuconazole or amphotericin B. Results: A total of 106 patients met the study criteria. Of these, 47 received isavuconazole, and 59 received amphotericin B as the primary treatment. The two cohorts had similar baseline characteristics, including a history of malignancy, use of immunosuppressants, infection sites, and pathogens. The amphotericin B group demonstrated a significantly greater incidence of renal disorders (p < 0.001) and hypokalemia (p < 0.001) than the isavuconazole group. The proportion of patients who received salvage therapy was greater in the amphotericin B group than in the isavuconazole group (42% vs. 6%, p < 0.001). Eighteen patients in the amphotericin B group discontinued treatment because of adverse events, whereas no patients in the isavuconazole group discontinued treatment because of adverse events. A significant difference in the primary therapeutic response between the isavuconazole and amphotericin B groups was noted (p = 0.013), with a higher treatment failure rate in the amphotericin B group (68% vs. 36%, p = 0.001). However, there were no significant differences in all-cause mortality or mucormycosis-attributable mortality rates between the two groups. Conclusions: Isavuconazole outperformed amphotericin B as a first-line treatment option for IM in terms of its clinical effectiveness and safety.