PURPOSE: Oral mucositis (OM) causes significant morbidity during the course of radiotherapy (RT) treatment of head-and-neck cancer. It is hypothesized that infection plays a role in the development of OM. We tested the efficacy of iseganan HCl (iseganan), a synthetic peptide with broad-spectrum antimicrobial activity, for preventing RT-associated OM.
METHODS: A multinational, randomized, double-blind, controlled trial was performed on patients receiving primary RT, primary chemoradiotherapy or postoperative RT. Patients were randomized to receive iseganan oral solution plus standard-of-care oral hygiene (SOC), placebo plus SOC, or SOC alone throughout the RT administration period. The severity of OM was assessed by NCI-CTC scoring and clinical symptoms by patient questionnaire.
RESULTS: A total of 545 patients were randomized to the study. Nine percent of the patients in both the iseganan and placebo groups did not develop ulcerative OM (Grades 2, 3, 4) (p = 0.998) whereas only 2% of the patients receiving SOC alone remained free of oral ulceration (p = 0.049). The maximum severity of mouth pain and difficulty swallowing did not differ in patients treated with iseganan or placebo. However, patients in both intervention groups reported less mouth pain and difficulty swallowing than did patients receiving SOC alone. Nausea was the only adverse event that occurred with >/=5% increased frequency in the iseganan group than in either the placebo or SOC groups (51% vs. 42% vs. 46%). Adverse events leading to study drug discontinuation and death did not differ significantly between groups.
CONCLUSION: Iseganan oral solution was safe but did not reduce the risk for developing ulcerative OM relative to placebo. Intensified oral hygiene or the administration of the vehicle used to deliver study drug in this trial appears to have reduced the risk and severity of OM. Our results suggest that antimicrobial intervention may not meaningfully affect the pathogenesis of radiation-induced OM.