(059) Differences in Time to Count Recovery Between Pegfilgrastim and Filgrastim in Pediatric Patients Receiving Interval Compressed Chemotherapy. (Top Ten Poster)

Poster Abstract:

Background:
Interval compressed chemotherapy (ICC) for Ewing’s sarcoma includes alternating vincristine, doxorubicin, cyclophosphamide (VDC) with ifosfamide and etoposide (IE) every two weeks and is considered the standard of care based on the results from AEWS0031. In AEWS0031, the biweekly schedule of ICC was supported with daily filgrastim (GCSF) injections until count recovery, which is burdensome and requires frequent lab monitoring. This begs the question, “Is there a role for long-acting GCSF in ICC?”. Pegfilgrastim (pegGCSF) has been used in non-compressed VDC/IE therapy previously and was shown to decrease the duration and severity of neutropenia when compared to GCSF. However, data is scarce in ICC. At Seattle Children’s Hospital pegGCSF has been the standard of care for neutrophil support during ICC despite the lack of published data to deny or support its use. We hypothesize that pegGCSF will yield similar if not improved time to count recovery in ICC when compared to the historical data with GCSF and will have similar incidence rates of adverse events.

Objectives:
The primary objective of this study is to compare the time to count recovery in patients receiving ICC supported by pegGCSF at Seattle Children’s Hospital to those receiving GCSF in AEWS0031. This study will also assess whether delays in therapy are due to neutropenia, thrombocytopenia, or both. Secondary objectives of this study are to determine the incidence of febrile neutropenia (FN), duration of hospital stay due to FN, and incidence of complications related to pegGCSF (ex. leukocytosis, secondary malignancy).

Methods:
This is a single center retrospective analysis of patients receiving ICC based on AEWS0031 with neutrophil support via pegGCSF. Data collection via electronic health record (EHR) review of patients treated from October 3, 2020 to present. Results from our institution will be compared to results from AEWS0031. Patients were included if they were treated with ICC based on AEWS0031 and received pegGCSF. Primary data to be collected includes chemotherapy cycles and timing, pegGCSF administration time, absolute neutrophil count (ANC), platelet count, and days until ANC above 750. Additional data to be collected includes patient specific details around their radiation therapy, incidence of FN, hyperleukocytosis and secondary malignancies. Research is approved by institutional review board (IRB).

Results: – Results pending

Discussion/

Conclusions: – Results pending

References (must also be included in final poster): 1. Wendelin G, Lackner H, Schwinger W, Sovinz P, Urban C. Once-per-cycle pegfilgrastim versus daily filgrastim in pediatric patients with Ewing sarcoma. J Pediatr Hematol Oncol. 2005;27(8):449-451. doi:10.1097/01.mph.0000175711.73039.63
2. Milano-Bausset E, Gaudart J, Rome A, et al. Retrospective comparison of neutropenia in children with Ewing sarcoma treated with chemotherapy and granulocyte colony-stimulating factor (G-CSF) or pegylated G-CSF. Clin Ther. 2009;31 Pt 2:2388-2395. doi:10.1016/j.clinthera.2009.11.013
3. Borinstein SC, Pollard J, Winter L, Hawkins DS. Pegfilgrastim for prevention of chemotherapy-associated neutropenia in pediatric patients with solid tumors. Pediatr Blood Cancer. 2009;53(3):375-378. doi:10.1002/pbc.22086
4. Womer RB, West DC, Krailo MD, et al. Randomized controlled trial of interval-compressed chemotherapy for the treatment of localized Ewing sarcoma: a report from the Children's Oncology Group [published correction appears in J Clin Oncol. 2015 Mar 1;33(7):814. Dosage error in article text]. J Clin Oncol. 2012;30(33):4148-4154. doi:10.1200/JCO.2011.41.5703