Abstract P4-12-19: BOLERO-3: Everolimus plus trastuzumab and vinorelbine in Asian patients with HER2-positive metastatic breast cancer

A single-arm, phase 2 study of steroid-containing mouthwash for the prevention of everolimus-associated stomatitis in multiple tumor types

BACKGROUND

Everolimus is a mammalian target of rapamycin inhibitor used in the treatment of multiple tumor types, and its most common toxicity, stomatitis, can affect patient quality of life. Recent studies in breast cancer have supported the efficacy of steroid mouthwash for the prevention of everolimus-associated stomatitis. However, a few studies have been reported to date, and none have examined this effect in other tumor types.

METHODS

This single-arm phase 2 study was designed to evaluate the efficacy of steroid-containing mouthwash for the prevention of stomatitis in patients with multiple tumor types receiving everolimus. The primary outcome was incidence of grade ≥ 2 stomatitis at 8 weeks of everolimus with steroid-containing mouthwash prophylaxis. We also assessed the stability of steroid-containing mouthwash components.

RESULTS

Twenty-nine patients were evaluated, of which 76% had breast cancer and 24% had neuroendocrine tumors originating in the lung, gastrointestinal tract, pancreas, or of unknown primary origin. Grade ≥ 2 stomatitis incidence at 8 weeks was 28.1% (90% CI 16.2-46.1); the higher confidence limit exceeded the prespecified threshold of 30%. No patients developed grade ≥ 3 stomatitis. Most stomatitis occurred behind the oral cavity, with no lesions observed on the lips or floor of the mouth.

CONCLUSIONS

Our findings did not support a prophylactic effect of steroid-containing mouthwash on everolimus-associated stomatitis. Given the needs of prevention of everolimus-associated stomatitis in various tumor types, further studies in a larger population using a randomized controlled trial design are, therefore, required to confirm the efficacy of steroid-containing mouthwash.