The FDA granted accelerated approval to dostarlimab (Jemperli) for adults with stage II or III locally advanced rectal cancer whose tumors are MSI-H or dMMR. The decision is based on the multicenter, single-arm AZUR-1 phase 2 trial. In the study, the primary endpoint—12-month sustained clinical complete response (cCR12) assessed by independent central review—reached 47% among evaluable patients. The objective response rate was 79%, and long follow-up reported no disease progression among patients achieving cCR12, cCR, or non-confirmed cCR within the reported outcomes set. The approval strengthens the role of immunotherapy in biomarker-defined rectal cancer settings and positions nonoperative management as a key part of future clinical and regulatory discussions for MSI-H/dMMR disease.