Abstract P5-15-19: Prophylaxis of chemotherapy-induced febrile neutropenia with biosimilar filgrastim: Description of patients, treatment patterns and outcomes in the MONITOR-GCSF study in the breast cancer cohort
Authors: Gascón Pere , Aapro Matti , Ludwig Heinz , Boccadoro Mario , Bokemeyer Carsten , Turner Matthew , Muenzberg Michael , Abraham Ivo , Denhaerynck Kris , MacDonald Karen 
Published: May 2015

Introduction: MONITOR-GCSF is a European prospective observational study of practice patterns and outcomes of patients treated with Sandoz' filgrastim (EP-2006) in the prophylaxis of chemotherapy-induced febrile neutropenia (CIN/FN).

Objectives: To describe patients, treatment patterns of EP-2006, and outcomes in the breast cancer cohort of the MONITOR-GCSF study.

Methods: Prospective observational study following 466 evaluable patients from 23 centers in Europe for up to 6 cycles within a single chemotherapy line including a total of 2714 cycles.

Results: Median age was 56y (range 25-91); all but 3 patients were female. Table 1 presents chemotoxicity in terms of % FN risk and prophylaxis type. GCSF was correctly initiated as either primary or secondary prophylaxis per EORTC guideline recommendations (considering chemotherapy-related FN risk and patient-related factors) in 62% of patients. Eleven percent were undertreated, i.e., secondary prophylaxis when primary was indicated–either when CIN/FN risk &gt;20% or when CIN/FN risk was 10-20% in combination with patient-related risk factors. Twenty-seven percent were overtreated, i.e., primary or secondary when not indicated–either primary prophylaxis in &lt;10% risk of CIN/FN or in 10-20% risk of CIN/FN in the absence of risk factors, or secondary prophylaxis in &lt;10% risk of CIN/FN in absence of prior CIN/FN. EP-2006 was started on average 2.8±2.6 days after chemotherapy was initiated and given for 4.9±2.1 days. Dosing was 45% at 30MIU/day, 55% at 48MIU/day. CIN (any grade) occurred in 12.0% of all cycles and 32.8% of patients had one or more episodes of CIN. 19.5% of patients had at least one episode of Grade 3 or 4 CIN of which 6.2% were febrile. CIN/FN-related hospitalizations were experienced by 5.2% of patients. CIN/FN-related chemotherapy disturbances (dose reduction, delay or cancellation) occurred in 9.4%.

Table 1  n%Chemotherapy toxicity (risk of FN)&gt;20%25053.8 10-20%17036.5 &lt;10%459.7PhrophylaxisPrimary37279.8 Secondary9420.2Prophylaxis decision relative to guidelinesUndertreated5010.8 Correct28962.1 Overtreated12627.1

Conclusions: Variation in treatment with biosimilar GCSF in breast cancer patients is evident in terms of decision to treat with primary prophylaxis relative to guideline recommendations as well as day of initiation, duration and dose, yet incidence of CIN/FN and related events is low. Forthcoming analyses will determine whether variability in treatment is associated with differential outcomes.

Citation Format: Pere Gascón, Matti Aapro, Heinz Ludwig, Mario Boccadoro, Carsten Bokemeyer, Matthew Turner, Michael Muenzberg, Ivo Abraham, Kris Denhaerynck, Karen MacDonald. Prophylaxis of chemotherapy-induced febrile neutropenia with biosimilar filgrastim: Description of patients, treatment patterns and outcomes in the MONITOR-GCSF study in the breast cancer cohort [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-15-19.