Use of Pegfilgrastim in Japanese Pediatric Patients With Solid Tumors: A Retrospective Analysis.

There are no detailed analyses of regarding pegfilgrastim usage in Japanese pediatric solid tumor patients. The approved dose of pegfilgrastim in Japan is 3.6 mg. We retrospectively evaluated the incidence of dose delays and dose reductions due to neutropenia in pediatric patients with solid tumors receiving chemotherapy with pegfilgrastim between 2015 and 2018. The effects of the timing of pegfilgrastim administration were evaluated. In chemotherapies administered every 2 and 3 weeks, prolongation of chemotherapy cycles was analyzed. Fifty-nine patients received chemotherapy with prophylactic pegfilgrastim for a total 247 cycles. No significant incidence of dose delays was observed with pegfilgrastim administration during the first 1 to 3 days after chemotherapy. When 77 cycles in 2-week regimens were compared with 166 cycles in 3-week regimens, mean cycle durations were 15.19±2.06 and 21.97±2.88 days, respectively (P<0.001). A total of 77 chemotherapy cycles administered every 14 days were subdivided. The incidence of dose delays in pediatric patients receiving chemotherapy for 5 consecutive days was similar to that for 1 day and 2 consecutive days. Pegfilgrastim prophylaxis could be of use for Japanese pediatric patients with solid tumors receiving chemotherapy, including administration every 2 weeks. Its use aids in maintaining the chemotherapy schedule.