·To observe the efficacy and safety of posaconazole in the prevention of invasive fungal disease (IFD) in patients with acute leukemia (AL) including myelodysplastic syndrome (MDS).

·The clinical data of 121 patients with AL (including MDS) treated in Ruijin Hospital,Shanghai Jiao Tong University School of Medicine from June 2016 to May 2021 were analyzed retrospectively. All the patients received clinical prophylaxis and treatment according to the Expert Consensus on ClinicalUse of Posaconazole. According to the study of China Assessment of Antifungal Therapy in Hematological Diseases (CAESAR), the patients were divided into three groups, including low-risk group, medium-risk group and high-risk group according to the IFD risk stratification, among which the efficacy and safety of posaconazole in different risk groups were observed. Patients proved or probable to have fungal infection while receiving posaconazole were considered to have breakthrough fungal infection. Patients who reported no fungal infection during the three-month follow-up after discontinuation were regarded as effective prophylaxis. If any fungal infection was found, it was regarded as a prevention failure. During the period of neutropenia, blood routine and body temperature were monitored daily, and liver and kidney function and electrolytes were tested three times a week. Whether the patients had gastrointestinal discomfort such as abdominal distension, diarrhea, nausea and vomiting during oral posaconazole or not was observed, and the electrocardiogram of the patients was monitored.

·A total of 121 cases were collected, including low-risk group (n=27), medium-risk group (n=40) and high-risk group (n=54). The incidence of breakthrough fungal infection was 3.31% (4/121), and the 4 patients were in the high-risk group. Abnormal liver function was the most common adverse reaction (20 cases); among them, 13 cases in the medium-risk group and high-risk group (10.74%, 13/121) changed the regimen because of treatment intolerance. According to the time of neutropenia, the prophylactic time of posaconazole was different among the groups. The average time of use of posaconazole was 16.85 d in the low-risk group, 18.90 d in the medium-risk group and 21.31 d in the high-risk group. The overall prevention effective rate of posaconazole was 85.95% (104 /121). There was no significant difference in the effective rate of prevention between the low-risk group (100%, 27/27) and the medium-risk group (95.00%, 38/40) (P=0.242), but the differences in the comparison of the high-risk group (72.22%, 39/54) with the low-risk group and the medium-risk group were both significant (P=0.003, P=0.005).

·Posaconazole is effective and safe in the prophylactic treatment of invasive fungal infection in patients with AL (including MDS), but liver function should be closely monitored in moderate and high risk patients.