G-CSF as Secondary Prophylaxis of Chemotherapy-Induced Neutropenia in Patients with Solid Tumors: Results of a Prospective, Observational Study

ABSTRACT Background There are little available data on secondary prophylaxis of chemo-induced neutropenia. We designed this multicentre, prospective and observational study to identify predictive factors of occurrence of neutropenic events (NE) subsequent to a previous episode, in patients with solid tumors (primary objective). Secondary objectives were to determine the incidence of NE, describe prophylactic strategy: cycle delay, dose reduction, G-CSF prescription, and its impact on the recurrence of NE. Patients and methods Patients ≥ 18 years were included if they experienced a NE during any previous cycle (reference cycle A), with no prior G-CSF administration. Neutropenic events were defined as any neutropenia grade 1-4, febrile or not, that impacts on the subsequent cycles (cycle delay and/or dose reduction and/or use of G-CSF). Patients were followed for a total of 5 cycles. Risk factors of febrile neutropenia (FN), and prophylactic strategies (with or without G-CSF) were included in univariate and multivariate analyses to assess their predictive value on recurrence of NE. Results 625 patients included, 548 (87.7%) evaluable.378 (69%) female, mean (SD) age (years) 61.7 (12.3), WHO PS 0-1 88.3%, breast: 40%, colorectal: 15.7%, lung: 11.9%. Metastatic disease: 53.3%. During cycle A, 88 patients (16.1%) experienced FN, 42 (7.7%) neutropenic fever and 418 (76.3%) neutropenia (any grade w/o fever). 44.5% had cycle delay, 22.3% dose reduction and 466 (85%) received prophylactic G-CSF (pegfilgrastim 59.7%, lenograstim 27.3%, filgrastim 10.3% and biosimilar 2.1%). Incidence of NE in subsequent cycles and prophylactic strategies are shown in the table below. In multivariate analysis, G-CSF use (HR:0.32 (0.24; 0.43; p  Conclusion Prophylactic strategy with G-CSF has significant efficacy in reducing the incidence of NE, and should be considered as the best option in the secondary prophyalxis setting. Cycle A (no G-CSF) N = 548 Cycle B N = 548 Cycle C N = 548 CycleD N = 442 Cycle E N = 344 Febrile neutropenia 88 (16.1%) 3 (0.5%) 4 (0.7%) 0 1 (0.3%) Neutropenic fever 42 (7.7%) 2 (0.4%) 4 (0.7%) 1 (0.2%) 0 Neutropenia w/o fever 418 (76.3%) 111 (20.3)% 95 (17.3%) 50 (11.3%) 47 (13.7%) Cycle delay - 244 (44.5%) 44 (8.0%) 23 (5.2%) 18 (5.2%) Dose reduction - 122 (22.3%) 27 (4.9%) 17 (3.8%) 12 (3.5%) use of Prophylactic G-CSF - 466 (85.0%) 413 (75.4%) 332 (75.0%) 247 (71.8%) Disclosure G. Freyer: Consultant for Amgen All other authors have declared no conflicts of interest.