1869P - Risk factors for reduced relative dose intensity (RDI) in patients with solid tumors receiving chemotherapy (CT) and primary prolonged G-CSF prophylaxis by empegfilgrastim: Analysis of DEFENDOR study

Background

Clinical guidelines mentioned that prior CT or radiation therapy (RT), persistent neutropenia, recent surgery and/or open wounds, liver and renal dysfunction, 65 y.o. age are important risk factors for chemotherapy-induced neutropenia (CIN) and FN during CT. G-CSF are routinely used for prevention of CIN and maintaining RDI. Therefore, there is a need to understand how risk factors are associated with RDI in pts with G-CSF primary prevention FN. Here we present the analysis of a multicenter prospective observational post-marketing study of safety and efficacy of prolonged G-CSF empegfilgrastim (JSC BIOCAD) in pts with solid tumors who receive cytotoxic therapy (NCT04811443).

Methods

The study included 3218 pts with various tumor types across 41 centers in Russia. The primary endpoint was the RDI of CT courses (4-8 cycles per course are allowed) with empegfilgrastim support. 2663 (82.8%) pts were included in the RDI assessment population. RDI was calculated for each single agent in the CT-based (CTb) regimen and for the CTb regimen in total. Multivariate logistic regression was used to estimate the association between RDI < 85% and the following variables: sex, age, ECOG, comorbidities, prior RT, Hb<12 g/dl.

Results

Logistic regression for RDI < 85% was estimated on 2624 pts with data available for all variables. Higher ECOG and prior RT are significantly associated with RDI < 85% (Table). Table: 1869P

Association of risk factors with RDI < 85%