A Phase II Study of Dostarlimab Immunotherapy in People with Locally Advanced "Mismatch Repair-Deficient" Rectal Cancer


Full Title

A Phase II Study of Induction PD-1 Blockade in Subjects with Locally Advanced Mismatch Repair Deficient Solid Tumors


Deficient mismatch repair (dMMR) happens when a cell becomes unable to repair mistakes that happen during the normal process of cell division. Standard treatments for early-stage rectal cancer include chemotherapy, radiation therapy, and surgery. In this study, researchers are assessing the safety and effectiveness of giving the investigational immunotherapy dostarlimab first in people with locally advanced mismatch repair-deficient rectal cancer. Doctors will then evaluate patients’ response to treatment before considering standard chemoradiation and/or surgery. Patients whose tumors respond completely to dostarlimab alone can be followed with close surveillance and no surgery. 

Dostarlimab is a type of medication called an antibody. It blocks another protein (PD-1) that usually acts as a “brake” on the immune system, thereby enabling the immune system to detect and destroy cancer cells.

Who Can Join

To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have stage II or III dMMR rectal cancer that has not been previously treated with chemotherapy, radiation therapy, or surgery.
  • Patients must be physically well enough that they are fully ambulatory, capable of all self-care, and capable of all but physically strenuous activities. As an example, patients must be well enough that they would be able to carry out office work or light housework.
  • This study is for patients age 18 and older.


For more information and to inquire about eligibility for this study, please contact Dr. Andrea Cercek at 646-888-4189.




Phase II (phase 2)

Disease Status

Newly Diagnosed


ClinicalTrials.gov ID