Velafermin (rhFGF-20) reduces the severity and duration of hamster cheek pouch mucositis induced by fractionated radiation

Purpose: Velafermin (recombinant human fibroblast growth factor-20, rhFGF-20) has been shown to reduce the severity and duration of mucositis in preclinical acute (single dose) radiation and chemotherapy/radiation models of oral mucositis. Our present study assessed the impact of velafermin on the severity and duration of oral mucositis that occurred as a consequence of fractionated radiation. Experimental design: Male Golden Syrian hamsters were exposed to eight doses of radiation (7.5 Gy/dose) to the cheek pouch on days 0, 1, 2, 3, 6, 7, 8 and 9 that resulted in severe mucositis. Velafermin (4 mg/kg intraperitoneally) was administered on days 3 and 9; days 2, 3, 8 and 9; days 3, 4, 9 and 10; or days 4, 5, 10 and 11. Results: Although all velafermin-treated groups showed some reduction in the degree of mucositis relative to the vehicle control, the most significant reduction (p<0.001) was observed in the groups treated on days 3 and 9 or on days 4, 5, 10 and 11. Further histological analysis of resected buccal mucosa revealed improvements in epithelial tissue degradation, connective tissue degradation and inflammation severity after velafermin treatment. Most notably, velafermin treatment reduced inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor (TNF) production possibly through nuclear factor-kappa B (NF-kappa B) mediation. The detection of increased NF-E2-related factor-2 (NRF-2) expression in the early onset stage of mucositis in the buccal mucosa suggested additional protective benefits from reactive oxygen species (ROS) generated as a consequence of fractionated radiation treatment. Conclusion: Thus, velafermin provided therapeutic benefit in a hamster model of oral mucositis induced by fractionated radiation therapy.