Filgrastim (r-metHuG-CSF) and its potential use in the reduction of radiation-induced oropharyngeal mucositis: An interim look at a randomized, double-blind, placebo-controlled trial

We wished to determine if filgrastim administration to chemotherapy/radiation therapy-naive patients receiving external-beam irradiation for head-and-neck malignancies would reduce the incidence and severity of oral/oropharyngeal mucositis. Patients were randomized to receive subcutaneous injections of either filgrastim or placebo beginning on day 1 of radiation and continuing daily throughout treatment. Study medication was titrated to keep the neutrophil count between 10 x 10(9) and 30 x 10(9)/l. The left and right buccal mucosa, hard palate, and posterior pharyngeal wall were scored weekly, by a blinded evaluator using two different scales, and the most severe score per week was used in data analysis. Fourteen of a planned 54 patients were randomized (8 filgrastim, 6 placebo), and were evaluable for a planned interim analysis. No statistically significant between-group differences were seen in mean worst scores across time using repeated measures analysis of variance (Hickey, p = 0.231; WHO, p = 0.288). At almost all timepoints, however, the worst mean scores were lower in patients treated with filgrastim compared with those in patients treated with placebo, and the number of severe (i.e., grade 3) mucositis scores was significantly lower in the filgrastim-treated group. Filgrastim may decrease the severity of radiation-induced oral/oropharyngeal mucositis.