Abstract OT2-6-14: Phase 2, single arm study of a steroid-based mouthwash to prevent stomatitis in women with hormone receptor–positive advanced breast cancer treated with everolimus plus exemestane

BACKGROUND: Stomatitis, the inflammation of mucous membranes lining the mouth and throat, is a frequent adverse event that is associated with the oral mTOR inhibitor everolimus and can significantly impact treatment adherence. Specific strategies to prevent and/or lessen the severity of everolimus-associated stomatitis are not well documented. Steroid mouthwashes and steroid gels or pastes used to treat recurrent aphthous stomatitis may be effective for stomatitis associated with everolimus. This phase 2, single-arm study will evaluate a steroid-based therapeutic intervention to prevent stomatitis (Grade ≥2) in breast cancer patients taking everolimus + exemestane. METHODS: Eligible participants will be patients with HR-positive, HER2-negative advanced breast cancer with no evidence of oral stomatitis or other oral pathology who have been prescribed everolimus + exemestane but have not yet started treatment. A baseline oral assessment will be conducted, and patients will be provided instructions on how to self-monitor for stomatitis, along with instructions to contact the study site at the first sign of oral pain or changes to the oral mucosa. All patients will be instructed to perform routine good oral care. Eligible patients will receive a steroid-based mouthwash (alcohol-free 0.5mg/5ml dexamethasone solution) prophylactically. Patients will be instructed to perform the mouthwash regimen four times per day and swish the mouthwash in mouth for a minimum of 120 seconds before spitting it out. Patients will be instructed to abstain from eating or drinking for at least an hour after taking the mouthwash. Mouthwash regimen will begin on the first day of everolimus after administration of the dose and patients will continue the regimen for the first 4 months of everolimus therapy. Primary endpoint is the incidence of stomatitis (Grade ≥2) at 2 months defined as meeting at least one of the following criteria: ≤50 on Normalcy of Diet Scale to assess oral intake and a rating of 7 on two consecutive days or a rating of 8, 9 or 10 on any one day using Visual Analog Scale to assess oral pain. Evidence of stomatitis must be confirmed by investigator on physical exam and/or phone call assessment. Secondary endpoints include average number of times per day the mouthwash regimen was performed and time to resolution of stomatitis (Grade ≥2) that occurs during the trial. Assuming a 13% absolute reduction in the rate of grade ≥ stomatitis from the historical control rate of 33% and one sided Type 1 error = 0.05 and power = 80%,73 evaluable patients will be needed. To account for 25% of the total patient population being non-evaluable, 97 patients will be enrolled for this study. Supported by funding from Novartis Pharmaceuticals Corporation. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-6-14.