The U.S. Food and Drug Administration (FDA) has granted accelerated approval to Jemperli (dostarlimab-gxly) for adults with stage II or III rectal cancer whose tumors have certain features called mismatch repair deficiency (dMMR) or high microsatellite instability (MSI-H). The approval, announced October 19, 2026, offers an immunotherapy-only approach that may allow some patients to avoid chemotherapy, radiation and surgery. An FDA-authorized tumor test must confirm that the cancer is dMMR or MSI-H.
Who may benefit?
This treatment is for people with locally advanced rectal cancer—cancer that has grown into nearby tissue or spread to nearby lymph nodes but has not spread to distant organs. The approval was supported by studies in patients who had not previously received treatment for their rectal cancer.
The terms dMMR and MSI-H describe problems with the system that repairs mistakes in a cell’s DNA. These problems can make cancer cells easier for the immune system to recognize. Jemperli helps immune cells attack cancer by blocking PD-1, a protein that can keep the immune system from responding to cancer cells.
What did the research show?
The approval was based primarily on the AZUR-1 clinical trial, which included 154 patients. Participants received Jemperli through an intravenous (IV) infusion every three weeks for up to nine doses, or about six months.
Among 116 patients whose results could be evaluated by an independent review team, 47% had a clinical complete response that lasted at least 12 months. This means that examinations and tests found no detectable signs of cancer during that period. The study’s treating doctors reported a higher rate—68% among 144 evaluable patients—based on their own assessments. These were separate assessments of the same trial, not results from different treatment groups.
At the time of the analysis, 71% of all treated patients had received Jemperli alone, had not needed additional cancer treatment and had not experienced cancer progression. Other patients received surgery, radiation or additional drug treatment. These findings suggest that some patients may be able to avoid standard treatments, but this outcome is not guaranteed.
What should patients know about safety and follow-up?
The most common side effects included fatigue, rash, diarrhea and itching. Jemperli can also cause the immune system to attack healthy organs and tissues, leading to reactions that may be severe or life-threatening.
Patients whose cancer becomes undetectable still need close follow-up with examinations and imaging to watch for its return. A clinical complete response does not establish that the cancer is permanently cured. Because this is an accelerated approval, continued follow-up is required to confirm that the treatment provides lasting benefit.
For patients with stage II or III rectal cancer, the approval highlights the importance of knowing their tumor’s dMMR or MSI-H test results and discussing how those results may affect treatment options with their cancer care team.
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