Febrile neutropenia (FN) occurrence outside of clinical trials: occurrence and predictive factors in adult patients treated with chemotherapy and an expected moderate FN risk. Rationale and design of a real-world prospective, observational, multinational study

BACKGROUND: Febrile neutropenia (FN) is a common occurrence during chemotherapy. Granulocyte colony-stimulating factors (G-CSFs) can significantly reduce the risk of FN. International guidelines recommend G-CSF for patients receiving chemotherapy with FN risk of ≥20% or 10% to 20% with defined risk factors. Prophylaxis is not typically recommended for FN risk of < 10%; however, few studies have investigated FN incidence in lower-risk patients in real-world settings and tried to identify higher-risk subgroups. METHODS: This real-world prospective, observational, multinational study aims to estimate the rate of development of FN with a chemotherapy line expected to be associated with a 10% to 20% risk of FN. Eligible patients (> 18 years of age) will have a solid tumour or Hodgkin/non-Hodgkin lymphoma and a planned chemotherapy regimen with expected risk of FN of 10% to 20% (according to published guidelines). Patients will be observed for the duration of the chemotherapy line (first cycle administered without FN prophylaxis). Primary endpoint is incidence of FN after the first chemotherapy cycle. Secondary outcomes include: FN-associated morbidity and mortality; time to first FN occurrence; other FN risk factors and impact of FN on quality of life. A risk model using occurrence of FN as a binary outcome will be developed. Data will be stratified by age, comorbidities and other risk factors. DISCUSSION: This study will provide insight into the real FN risk for common chemotherapy regimens and predictive factors for FN, including patients generally excluded from randomised clinical trials, from which reported FN rates have been variable. This study builds on knowledge of predictive factors from other research and will provide information on patients with 10% to 20% FN risk.