Characterization of the Use and Efficacy of Isavuconazonium Sulfate in a Pediatric Oncology and Stem Cell Transplant Population: A Single Institution Retrospective Review.

Isavuconazonium sulfate (ISA) is a triazole antifungal approved for the treatment of invasive aspergillosis and mucormycosis in adults. This single-center, retrospective review of pediatric oncology and stem cell transplant patients receiving ISA for prophylaxis (n=20) or treatment (n=6) of invasive fungal disease (IFD) aims to characterize real-world clinical efficacy and toxicity of ISA in patients <18 years of age. Of 20 patients receiving ISA for prophylaxis, three patients had presumed breakthrough IFD (1 proven, 2 probable/possible). No adverse effects were attributed to ISA use or led to the discontinuation of therapy.

Letermovir for Cytomegalovirus Prevention in Adolescent Patients Following Hematopoietic Cell Transplantation.

There are limited data for letermovir as primary cytomegalovirus (CMV) prophylaxis in patients less than 18 years of age. We report 9 adolescent patients who received letermovir following hematopoietic cell transplantation. No patients developed clinically significant CMV while taking letermovir. Letermovir was well tolerated and efficacious in preventing CMV infections.

Concurrent Imatinib Dosing With High-dose Methotrexate Leads to Acute Kidney Injury and Delayed Methotrexate Clearance in Pediatric Patients With Philadelphia Chromosome-positive B-Cell Acute Lymphoblastic Leukemia.

Imatinib, a tyrosine kinase inhibitor has improved survival in pediatric patients with Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia. There are no formal drug interactions listed between methotrexate and tyrosine kinase inhibitors. Four pediatric patients with Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia had delayed methotrexate clearance during their first cycle of high-dose methotrexate while receiving imatinib, resulting in acute kidney injury. For subsequent high-dose methotrexate cycles, imatinib was withheld resulting in decreased acute kidney injury, shorter time to methotrexate clearance, less toxicity, and shorter hospitalizations. For pediatric patients with acute lymphoblastic leukemia receiving imatinib, we recommend escalated supportive care measures including increased hyperhydration and leucovoruin frequency. For patients with toxicities secondary to delayed clearance or need for glucarpidase, we recommend holding imatinib with subsequent high-dose methotrexate courses.