5PSQ-028 Prescription profile of isavuconazole in the real world clinical practice

Background and importance Early antifungal therapy for invasive pulmonary aspergillosis has been associated with better survival outcomes in immunocompromised patients. Isavuconazole, as well as caspofungin and liposomal amphotericin B (LAmB), is a recommended alternative to voriconazole when contraindicated due to its toxicity or pharmacokinetic profile. Aim and objectives To assess the efficacy and safety of isavuconazole therapy in patients diagnosed with invasive fungal disease (IFD) in clinical practice. Material and methods A retrospective observational study was performed in a third level hospital. Patients treated with isavuconazole between December 2017 and October 2019 were included. Demographic, clinical and therapeutic variables were collected. Diagnostic criteria of IFD were assessed in accordance with the European Organisation for Research and Treatment of Cancer/Infectious Diseases Mycoses Study Group (EORCT/MSG). These data were obtained from electronic medical records. Results Fifteen patients were recruited: 64% men, mean age 50±17 years. Median days of treatment was 47 (IQR 47–142). Doses were prescribed following the drug’s label. The main diagnosis was haematological malignancy (73.3%), 81.8% of which had undergone haematopoietic stem cell transplantation. IFDs included: proven (n=0), probable (n=6) and possible (n=4) aspergillosis; and possible mucormycosis (n=1). One patient was diagnosed with aspergillus vertebral osteomyelitis. Overall, 53.3% of patients had previously been treated with voriconazole, 20% with LAmB, 20% were treatment naive and one patient was treated with posaconazole for mucormycosis. Reasons for drug switching were: to avoid potential drug interactions (40%); voriconazole related adverse effects (33%); LAmB toxicity in one patient; ineffectiveness in one patient; and isavuconazole’s better safety profile in another patient. However, hepatobiliary adverse effects were reported in 26.6% of patients and ocular toxicity in 6.7%. Regarding the efficacy of isavuconazole, 26.6% of patients died during treatment and only two patients were considered cured. At the time of data cut-off, only one patient was continuing treatment. Conclusion and relevance Isavuconazole appears to be an emerging therapy for IFDs in our hospital. Its better pharmacokinetic profile and tolerance means a therapeutic option for complicated patients. Nevertheless, the poor prognosis hinders efficacy assessment in this setting and hence a more cost effectiveness selection among the available antifungals should be performed. References and/or acknowledgements No conflict of interest.