Dexamethasone Mouthwash for Everolimus-Related Mouth Sores in Breast Cancer Treatment

The medicine containing the active ingredient everolimus, Afinitor , received approval in 2012 for use with Aromasin (active ingredient exemestane) to treat advanced, hormone-positive, Her2-negative breast cancer in postmenopausal patients from the FDA .

Intracellular growth pathwaysinclude mTOR, which everolimus blocks. One of its main side effects is stomatitis, or mouth sores. Topical (locally applied) steroids can ease the extent and severity of mouth sores, and discomfort caused by everolimus may require a dose reduction.

Earlier studies had reported that steroid (cortisone) mouthwash might prevent mouth sores. A study published in March 2017 in Lancet Oncologyinvestigated whether dexamethasone mouthwash could prevent mouth sores in patients with breast cancer taking everolimus.

This United States-based, multicenter, single-arm phase-2 prevention study included 92 postmenopausal women with metastatic, hormone receptor-positive, HER2-negative breast cancer. On the first day, patients received 10 mg everolimus and 25 mg exemestane, along with 10 ml alcohol-free dexamethasone mouthwash. After 8 weeks, patients were permitted to use dexamethasone mouthwash for an additional 8 weeks with the shared knowledge of the patient and physician.

Preparing the Mouthwash: An alcohol-free solution containing 0.5 mg dexamethasone per 5 ml oral solution was swished around the mouth for 2 minutes and then spat out. A timer was used. This was repeated four times daily for 8 weeks. Patients were instructed not to take anything by mouth for 1 hour after using the dexamethasone oral solution.

Between 28 May 2014 and 8 October 2015, 92 women enrolled, and 85 were evaluable for treatment benefit. After 8 weeks, grade 2 or higher stomatitis (mouth sores) occurred in only 2 of the 85 patients. Overall, at least 1 side effect was seen in 83 of the 92 patients receiving everolimus and exemestane. The most frequently recorded grade 3 and 4 side effects were hyperglycemia (high blood sugar), rash, and dyspnea (shortness of breath). Serious reported side effects occurred in 20 patients; 2 were considered treatment-related, with dyspnea and pneumonia most common. Everolimus and exemestane treatment was discontinued because of side effects in 12 of the 92 patients.

In conclusion, prophylactic (preventive) dexamethasone oral solution reduced the extent and severity of mouth sores and may provide a new standard of oral care for patients receiving everolimus and exemestane.

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