ASCO 2016: News in Metastatic Breast Cancer - Abstract 525

Metastatic Breast Cancer

ASCO 2016. Abstract 525. Prevention of everolimus/exemestane (EVE/EXE) stomatitis in postmenopausal (PM) women with hormone receptor-positive (HR+) metastatic breast cancer (MBC) using a dexamethasone-based mouthwash (MW): Results of the SWISH trial.

Hope S. Rugo et al.

Results: Prophylactic use of 0.5 mg/5 mL dexamethasone QID was studied for the prevention of mucositis due to everolimus. 92 women were enrolled with 86 being evaluable for efficacy. Median age was 61 yrs (range 34-87); with 38% treated with EVE/EXE in the ≥ 2nd-line setting. Median dose intensity was 10 (range 3-14) and 25 mg (range 8-25) for EVE and EXE. 95% of pts used the MW 3-4 times/day (median MW use/d = 3.95, range 1.9-4). The rate of ≥ Gr 2 stomatitis at 8 weeks was 2.4% (2 pts) with a Gr 1 rate of 17.4%; there were no ≥ Gr 3 events. A comparison of stomatitis incidence by grade between BOLERO-2 and SWISH is shown in the Table. Mean pain scale score was < 1 at all visits; 86% of pts reported a normal diet at 8 wks. 12% discontinued EVE/EXE due to suspected related adverse events (most common: rash [2%], hyperglycemia [2%], stomatitis [1%] and pneumonitis [1%]). 

Conclusions: Prophylactic use of 0.5 mg/5 mL dexamethasone oral solution markedly decreases the incidence and severity of stomatitis in patients receiving EVE/EXE for MBC compared to the rates and severity observed in the BOLERO-2 trial and should be considered a new standard of care in this setting. Clinical trial information: NCT02069093

CARE Faculty Perspective: CARE Faculty Perspective: The BOLERO-2 trial observed a 57% reduction in the risk of disease progression with the addition of everolimus to exemestane. Stomatitis was one of the most significant complications associated with mTOR inhibition and was dose limiting for many patients on the pivotal trial.
The SWISH trial used a dexamethasone based mouthwash to help reduce the incidence and severity of stomatitis, and observed stomatitis rates that were significantly lower than in BOLERO-2. We can conclude that this dexamethasone based mouthwash can help to optimize adherence and quality of life for patients receiving the treatment combination of everolimus with exemestane.