A prospective study to evaluate febrile neutropenia incidence in patients receiving pegfilgrastim on-body injector vs other choices

PURPOSE: We evaluated the incidence of febrile neutropenia (FN) and related clinical outcomes among patients treated with myelosuppressive chemotherapy for nonmyeloid malignancies who received pegfilgrastim on-body injector (OBI) or other options (Other) for FN prophylaxis. METHODS: In this prospective observational study, adult patients with breast, prostate, or lung cancer, or non-Hodgkin lymphoma at risk for FN were stratified into subgroups based on FN prophylaxis used in the first chemotherapy cycle: pegfilgrastim OBI vs Other (pegfilgrastim or biosimilar pegfilgrastim prefilled syringe, daily filgrastim, or no granulocyte colony–stimulating factor [G-CSF]) for up to 4 planned chemotherapy cycles. RESULTS: This US study enrolled 2575 eligible patients (OBI, 1624; Other, 951). FN incidence was lower in the OBI group (6.4% [95% CI, 5.2–7.6%]) than in the Other group (9.4% [7.5–11.2%]), with a relative risk (RR) of 0.66 (0.47–0.91; p = .006). A decreased risk of dose delays among patients receiving pegfilgrastim OBI vs Other was observed (RR for ≥ 5 days: 0.64 [0.42–0.96], p = .023; RR for ≥ 7 days: 0.62 [0.40–0.91], p = .016). Adherence, defined as G-CSF support for all chemotherapy cycles, was 94.0% (92.9–95.2%) in the OBI group compared with 58.4% (55.2–61.5%) in the Other group. Compliance with pegfilgrastim, defined as administration the day after chemotherapy, was 88.3% in the OBI group and 48.8% in the prefilled syringe group. CONCLUSION: Patients receiving pegfilgrastim OBI had a lower incidence of FN compared with those receiving alternatives. The OBI was associated with improved adherence to and compliance with clinically recommended G-CSF prophylaxis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00520-022-07226-9.