A Study of Dostarlimab vs Placebo After Chemoradiation in Adult Participants With Locally Advanced Unresected Head and Neck Squamous Cell Carcinoma

To join this study, you need to be an adult with a new diagnosis of head and neck squamous cell carcinoma in areas like your mouth, throat, or voice box. Your cancer must be locally advanced, meaning it hasn't spread to distant parts of your body, and surgery wasn't an option. You must have recently finished a specific chemotherapy and radiotherapy treatment.

Also, your doctors need to have taken a sample of your cancer before your chemotherapy and radiotherapy and found certain markers on it. Your overall health should be reasonably good, meaning you can perform most daily activities without too much difficulty, and your body's organs should be working well.

You cannot join if you've had other types of treatment for head and neck cancer before, or if your cancer started in different areas of your head or neck. If you've had certain severe side effects from similar drug treatments in the past, or unfortunately have more than one head and neck cancer, you also wouldn't be able to participate.

If you decide to take part in this study, you will be assigned by chance to receive either Dostarlimab or a placebo (a dummy treatment). Both will be given after your chemotherapy and radiotherapy have finished. You will have regular visits to the hospital for examinations, blood tests, and to receive your study treatment. The doctors and nurses will closely monitor your health and any side effects you might experience. These assessments are important to track how you are responding to the treatment and to ensure your safety. The exact number of visits, tests, and the total length of your participation will be explained in detail by the study team, but it will involve ongoing follow-up for a period after the treatment itself.