Study of Dexamethasone Mouthwash to Prevent Mouth Sores from Datopotamab Deruxtecan in Adults With Advanced Breast Cancer or EGFR-Mutated Lung Cancer

What this Trial Is About

Researchers are evaluating the use of dexamethasone mouthwash as a preventive treatment for stomatitis related to Datopotamab Deruxtecan Dato-DXd in patients with metastatic or inoperable locally recurrent breast cancer or advanced or metastatic EGFR-mutated non-small cell lung cancer. This Phase IV, open-label, single-arm study aims to describe how often and how severe grade 2 or higher stomatitis occurs in participants receiving this prophylactic mouthwash during the first 12 weeks of Dato-DXd treatment. Participants will receive dexamethasone 0.5 mg5 mL alcohol-free mouthwash, swishing 10 mL four times daily for about 2 minutes and then spitting it out without swallowing. They must avoid food or drink for at least 30 minutes after use. This mouthwash will be used throughout their standard care treatment with Dato-DXd. The study includes two groups one with breast cancer and one with lung cancer patients, enrolling about 100 participants total over 18 months. During the study, participants will be monitored for stomatitis incidence and severity up to 12 weeks after starting treatment, with additional assessments up to about 21 months for onset and resolution timing. Researchers will also track adherence to the mouthwash, any dose changes in Dato-DXd due to stomatitis, and overall safety. Follow-up for safety continues for 28 days after the last study dose, with various evaluations including clinical assessments throughout the treatment period.

An Open-label, Single-arm Study of Prophylaxis for Datopotamab Deruxtecan (Dato-DXd) -Related Stomatitis in Eligible Patients With Metastatic or Inoperable Locally Recurrent Breast Cancer or Locally Advanced or Metastatic Epidermal Growth Factor Receptor-Mutated Non-small Cell Lung Cancer.