Background: Plerixafor is approved in Japan for hematopoietic stem cell mobilization prior to autologous transplant, but limited data are available on the use in children. This study evaluates the safety and effectiveness of plerixafor in Japanese children aged <15 years.
Methods: A multicenter, post-marketing surveillance study was conducted in Japan to evaluate the safety and effectiveness of plerixafor in routine clinical practice. This subgroup analysis examined the safety and effectiveness of plerixafor administered as a once-daily, subcutaneous injection in children aged <15 years. The primary effectiveness outcome was the proportion of patients with 2 × 106 cells CD34+ cells/kg collected via apheresis within 4 days.
Results: Eighteen patients with solid tumors were included in this analysis; (median age 6.0 years, range, 1-13 years). In addition to granulocyte colony-stimulating factor, all patients had received chemotherapy immediately prior to plerixafor administration. The mean (SD) daily dose of plerixafor was 0.24 (0.01) mg/kg. Seven of the 18 patients (38.9%) developed adverse drug reactions (ADRs), all occurring in patients aged ≥6 years and weighing ≥16 kg. The most common ADRs were pyrexia (n = 4), vomiting (n = 3), nausea (n = 2), and abdominal pain (n = 2). Twelve patients (66.7%) achieved a CD34+ cell count ≥2 × 106 cells/kg within 4 days after the start of plerixafor administration.
Conclusions: The results provide an encouraging sign that plerixafor 0.24 mg/kg may be safe and effective in pediatric patients in routine clinical practice in Japan, but further research in larger studies is needed.
Keywords: autologous stem cell transplantation; children; plerixafor; post-marketing surveillance; solid tumors.
© 2022 The Authors. Pediatrics International published by John Wiley & Sons Australia, Ltd on behalf of Japan Pediatric Society.