Epigallocatechin-3-gallate mouthwash protects mucosa from radiation-induced mucositis in head and neck cancer patients: a prospective, non-randomised, phase 1 trial

Radiation-induced oral mucositis has a dismal outcome with limited treatment options. We conducted a phase I study to evaluate the safety and preliminary efficacy of epigallocatechin-3-gallate (EGCG) mouthwash when given along with radiation in head and neck cancer. Patients with pathologically confirmed head and neck cancer were eligible for this study. EGCG mouthwash was administered at the assigned dosage level (starting at 440 μmol/L, three times a day) in a standard 3 + 3 dose escalation design. Mucosal toxicity, patient satisfaction, and mucositis-related pain (MTP) were assessed weekly. The primary endpoint was safety of EGCG, and the secondary endpoint was to determine the relief of the mucositis symptom. The pre- and post-treatment parameters were compared using the paired t-test. 20 patients were enrolled. The maximum tolerated dose of the EGCG mouthwash was 2200 μmol/L. Burning (n = 1/20) and nausea (n = 3/20) were the most common toxicities. No patients experienced WHO Grade 3 or higher mucositis. MTP scores significantly decreased after EGCG administration over time (p < 0.05). Adding EGCG mouthwash to radiotherapy is feasible without increasing toxicities. The recommended dose for phase II study is determined to be 1760 μmol/L, and EGCG administration reduces radiation-induced oral mucosal injury in patients.