Abstract P4-03-33: A Population-based Analysis of Prophylactic G-CSF Biosimilar and Originator Administration over time among Patients Diagnosed with Breast Cancer
Authors: Pawloski Pamala A. , McDermott Cara L , Benitez Gabriela Vazquez , DeFor Terese , Mendelsohn Aaron B. , Marshall James , Moyneur Erick , Lockhart Catherine 
Published: March 2023

Abstract
A Population-based Analysis of Prophylactic G-CSF Biosimilar and Originator Administration over time among Patients Diagnosed with Breast Cancer Pawloski PA1, McDermott CL2, Vazquez Benitez G1, DeFor T1, Mendelsohn A3, Marshall J3, Moyneur E4, Lockhart CM2; on behalf of the G-CSF Comparative Effectiveness Research Team. 1HealthPartners Institute, Bloomington MN USA 2Biologics and Biosimilars Collective Intelligence Consortium, Alexandria VA USA 3Harvard Pilgrim Healthcare Institute, Boston MA USA 4StatLog, Montreal QC Canada Objectives: To characterize G-CSF product use, including product switching, among patients diagnosed with breast cancer in the Biologics and Biosimilars Collective Intelligence Consortium’s (BBCIC) Distributed Research Network (DRN). Methods: A retrospective analysis of electronically extracted insurance claims from 2015-2019 at 4 Research Partner Sites was conducted. Patients aged &gt;=20 years with a diagnosis of breast cancer who received chemotherapy associated with a risk of febrile neutropenia (FN) risk per National Comprehensive Cancer Network guidelines and any prophylactic granulocyte-colony stimulating factor (G-CSF), defined as before day 2 of the first cycle of chemotherapy were included. Results: A total of 11,788 patients were included; 89 (0.8%) were male sex per insurance records. The age distribution was 5,743 (49%) 50-64 years; 4,296 (36%) 20-49 years, and 1749 (15%) 65+ years. Chemotherapy regimens included cyclophosphamide/doxorubicin (n=7,377), carboplatin/docetaxel/trastuzumab/pertuzumab (n=1,862), cyclophosphamide/docetaxel (n=1,383), carboplatin/docetaxel/trastuzumab (n=430), cyclophosphamide/docetaxel/doxorubicin (n=147), and docetaxel/trastuzumab/pertuzumab (n=128). Overall, 218 patients (1.8%) developed FN during the first chemotherapy cycle. G-CSF utilization was pegfilgrastim 10,895 (92%), pegfilgrastim-cbqv 315 (3%), pegfilgrastim-jmdb 225 (2%), filgrastim 156 (1%), filgrastim-sndz 118 (1%), tbo-filgrastim 46 (&lt; 1%), a combination of pegfilgrastim+filgrastim 26 (&lt; 1%), and a combination of filgrastim+biosimilar 7 (&lt; 1%) received. A total of 10,953 (93%) patients received high-risk chemotherapy and G-CSF utilization was 10,162 (93%) pegfilgrastim, 288 (3%) pegfilgrastim-cbqv, 200 (2%) pegfilgrastim-jmdb, 132 (1%) filgrastim, 101 (&lt; 1%) filgrastim-sndz, 40 (&lt; 1%) tbo-filgrastim, and 30 (&lt; 1%) combination of products. Eight hundred fifteen (7%) patients received intermediate-risk chemotherapy and G-CSF utilization was, 716 (88%) pegfilgrastim, 27 (3%) pegfilgrastim-cbqv, 25 (3%) pegfilgrastim-jmdb, 23 (3%) filgrastim, 16 (2%) filgrastim-sndz, 5 (&lt; 1%) tbo-filgrastim, and 3 (&lt; 1%) combination. Twenty patients received low risk chemotherapy and of those 17 (85%) received pegfilgrastim. In 2019, the first full year of pegfilgrastim biosimilar availability, pegfilgrastim use was 76% pegfilgrastim, 13% pegfilgrastim-cbqv, and 9% pegfilgrastim-jmdb. Most patients who received a second cycle of chemotherapy received the same G-CSF product in the second cycle, specifically 67% received filgrastim, 71% tbo-filgrastim, 73% filgrastim-sndz, 96% pegfilgrastim, 84% pegfilgrastim-cbqv, and 81% pegfilgrastim-jmdb. Conclusions: The most common chemotherapy agents included cyclophosphamide, carboplatin, doxorubicin, docetaxel, or pertuzumab. Pegfilgrastim biosimilar uptake occurred following market availability. Within each G-CSF product, most patients received the same product during the second cycle of chemotherapy rather than switching products.
Citation Format: Pamala A. Pawloski, Cara L McDermott, Gabriela Vazquez Benitez, Terese DeFor, Aaron B. Mendelsohn, James Marshall, Erick Moyneur, Catherine Lockhart. A Population-based Analysis of Prophylactic G-CSF Biosimilar and Originator Administration over time among Patients Diagnosed with Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-33.