Risk of chemotherapy-induced febrile neutropenia with early discontinuation of pegfilgrastim prophylaxis based on real-world data from 2010 to 2015

Abstract

Objective: Evidence suggests that not all cancer chemotherapy patients who receive first-cycle pegfilgrastim prophylaxis (PP) continue to receive it in later cycles, and that these patients may be subsequently at higher risk of febrile neutropenia (FN). Available evidence, however, may not be reflective of current clinical practice. We undertook an evaluation to estimate the odds of FN, beginning with second chemotherapy cycle, among patients who received PP in that cycle and all previous cycles versus those who received PP in all previous cycles only, using recent real-world data.

Methods: A matched-cohort design and data from two US healthcare claims repositories (2010–2015) were employed. The source population comprised cancer patients who received intermediate/high-risk chemotherapy and first-cycle PP. From the source population, beginning with the second cycle, all patients who received PP in all previous cycles were identified. From this subset, patients who did not receive PP in the cycle of interest (“comparison patients”) were matched to those who received PP in that cycle (“PP patients”); the same process was repeated for subsequent cycles. Odds ratios (ORs) for FN (broad and narrow definitions) were estimated using generalized estimating equations.

Results: Among 47,254 patients in the source population, 9% did not receive second-cycle PP and were matched to those who did. FN odds in cycle 2 were significantly higher among comparison patients versus PP patients (OR [broad definition]: 1.7, p < .001); OR [narrow definition]: 4.3, p < .001). Results for subsequent cycles and for the last cycle, respectively, were comparable (OR [range, broad definition]: 1.6 to 3.1, p < .001 for all; OR [range, narrow definition]: 2.7 to 11.8, p < .001 for all).

Conclusions: In this real-world evaluation of cancer chemotherapy patients who received first-cycle PP, FN risk was substantially higher among patients who did not receive PP in subsequent cycles versus those who continued PP.

Keywords:

• Febrile neutropenia
• pegfilgrastim
• granulocyte colony-stimulating factor

Transparency

Declaration of funding

Funding for this research was provided by Amgen Inc. to Policy Analysis Inc. (PAI).

Author contributions: Authorship was designated based on the guidelines promulgated by the International Committee of Medical Journal Editors (2004). All persons who meet criteria for authorship are listed as authors on the title page. The contribution of each of these persons to this study is as follows: (1) conception and design (M.B., D.C., D.W.), acquisition of data (M.B., D.C., D.W.), analysis or interpretation of data (all authors); and (2) preparation of manuscript (R.D., D.W.), critical review of manuscript (M.B., D.C., H.W.). The study sponsor reviewed the study research plan and study manuscript; data management, processing, and analyses were conducted by PAI, and all final analytic decisions were made by study investigators. All authors have read and approved the final version of the manuscript.

Declaration of financial/other relationships

D.W., H.W. and R.D. have disclosed that they are employed by PAI. M.B. and D.C. have disclosed that they are employed by, and are stockholders in, Amgen Inc.

CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.