Pegfilgrastim and filgrastim patterns of use in community oncology practices: Results of the ACCEPT study

Abstract

6113 Background: In pivotal trials, appropriate use of pegfilgrastim and filgrastim prevented neutropenic complications when initiated in cycle (C) 1, 24h after chemotherapy (CT). In practice, filgrastim initiation has varied from C1 (primary protection) to later cycles (secondary prophylaxis). Within cycle, filgrastim has been initiated within 3 days of CT (proactive), delayed until nadir (reactive), or to treat febrile neutropenia. Pegfilgrastim’s (Neulasta) patterns of use and its impact on filgrastim use are largely unknown. Methods: 99 US community practices, stratified by CT use, participated in a large retrospective chart review. Consecutive records were abstracted for adult pts receiving CT in 2001 with filgrastim support (pre-pegfilgrastim launch) or in 2003 with filgrastim or pegfilgrastim support (post-pegfilgrastim launch). CT was initiated from Jan 1 to Dec 31 in 2001 or 2003. Results: 3782 charts documented pegfilgrastim or filgrastim use; 829 pts received filgrastim in 2001, 1031 pts in 2003, and 1922 pts received pegfilgrastim in 2003. The most common cancers were breast (49%), lung (21%) and NHL (16%). CT cycle length was mostly Q3W. Pegfilgrastim was initiated in C1 in 64% of pts, 84% by C2. Pegfilgrastim was initiated within 72h of CT in 86% of cycles. Patterns of use were independent of tumor type and cycle length. Filgrastim was initiated in C1 in 54% of pts, 76% by C2. Initiation within 72h of CT occurred in 46% of cycles. Within C1, initiation occurred >10 days after CT in 48% of pts. Comparing filgrastim use in 2001 to 2003, the proportion of pts with ≥8 days of use was reduced from 32% to 20%, respectively and 1–3 days of use was increased from 31% to 46%, respectively. An additional 580 pts received both pegfilgrastim and filgrastim; most received filgrastim and converted to pegfilgrastim (61%). Conclusions: In this community practice evaluation, appropriate use of pegfilgrastim was generally observed. Appropriate use of filgrastim was inconsistently documented, appearing often to be administered after neutropenic complications. Since pegfilgrastim’s introduction, filgrastim’s pattern of use has changed. In current practice, filgrastim no longer represents the community standard. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Amgen Amgen