Abstract
PURPOSE: Contrary to the approved indication for pegfilgrastim prophylaxis, some patients receive it on the same day as the last administration of chemotherapy in clinical practice, which could adversely impact risk of febrile neutropenia (FN). An evaluation of the timing of pegfilgrastim prophylaxis and FN risk was undertaken. METHODS: A retrospective cohort design and data from two US private health care claims repositories were employed. Study population comprised adults who received intermediate/high-risk chemotherapy regimens for solid tumors or non-Hodgkin's lymphoma (NHL) and received pegfilgrastim prophylaxis in ≥1 cycle; all cycles with pegfilgrastim were pooled for analyses. Odds ratios (OR) for FN during the cycle were estimated for patients who received pegfilgrastim on the same day (day 1) as the last administration of chemotherapy versus days 2-4 from chemotherapy completion. RESULTS: The study population included 45,592 patients who received pegfilgrastim in 179,152 cycles (n = 37,095 in cycle 1); in 12 % of cycles, patients received pegfilgrastim on the same day as chemotherapy. Odds of FN were higher for patients receiving pegfilgrastim prophylaxis on the same day as chemotherapy versus days 2-4 from chemotherapy in cycle 1 (OR = 1.6, 95 % CI = 1.3-1.9, p < 0.001) and all cycles (OR = 1.5, 95 % CI = 1.3-1.6, p < 0.001). CONCLUSIONS: In this large-scale evaluation of adults who received intermediate/high-risk regimens for solid tumors or NHL in US clinical practice, FN incidence was found to be significantly higher among those who received pegfilgrastim prophylaxis on the same day as chemotherapy completion versus days 2-4 from chemotherapy completion, underscoring the importance of adhering to the indicated administration schedule.