A Study of Dostarlimab in Untreated dMMR/MSI-H Locally Advanced Rectal Cancer

To be considered for this study, you would need to have rectal cancer that is in its early stages (Stage II or III) and has not spread to distant parts of your body. Doctors would also need to be able to see and assess your cancer using scans and a camera test (endoscopy). Crucially, tests on your cancer cells must show that it is a specific type, known as 'dMMR' or 'MSI-H'. You must not have had any previous treatment for this rectal cancer, such as radiation, chemotherapy, or surgery.

There are also some reasons why you might not be able to join. For example, if your cancer has already spread to other organs (known as metastatic disease), or if you have had certain lung conditions in the past. Also, if you've had severe allergic reactions to similar types of medicines or have certain active autoimmune diseases that need ongoing treatment, you likely wouldn't be able to participate. The study also cannot include individuals who have recently had or need an organ or stem cell transplant from a donor.

If you join this study, you will receive the study drug, dostarlimab. After treatment, doctors will closely monitor your condition. This involves going for regular check-ups, scans, and other tests to see how you are doing and to ensure the cancer has remained gone. The study aims to see if you can avoid chemotherapy, radiation, and surgery. While the total duration isn't specified, these types of studies typically involve regular visits during treatment and then follow-up visits for several years.