FDA Approves Jemperli for Certain Rectal Cancers: Who May Qualify and What It Means

• The FDA approved Jemperli as a single-agent treatment for some adults with previously untreated stage II or III locally advanced rectal cancer whose tumors are dMMR or MSI-H.
• The approval is based on interim results, and it does not mean every rectal-cancer patient can skip chemotherapy, radiation, or surgery.
• Patients need biomarker testing and close follow-up with an oncology team because the cancer can still recur or require standard treatment.

What the FDA approved on October 19, 2026

The U.S. Food and Drug Administration granted accelerated approval to Jemperli, also called dostarlimab-gxly, as a single-agent treatment for certain adults with previously untreated stage II or stage III locally advanced rectal cancer.

There is a key limitation: the tumor must be mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H). The result must come from an FDA-authorized test for solid tumors.

These cancers have usually grown into nearby tissue or reached nearby lymph nodes, but they have not spread to distant organs. The approval is not for every rectal cancer, every colorectal cancer, or every stage of disease.

Jemperli is an immunotherapy that blocks PD-1, a signal that can help cancer cells avoid immune-system attacks. Tumors with dMMR or MSI-H features often contain many DNA errors, which can make them more visible to the immune system and more responsive to checkpoint inhibitors.

Who may qualify for Jemperli?

Based on the FDA approval, a patient generally needs to meet all of these conditions:

• Be an adult.
• Have stage II or stage III locally advanced rectal cancer.
• Have previously untreated disease.
• Have a tumor that is dMMR or MSI-H.
• Have testing performed with an FDA-authorized test.

Only a small portion of locally advanced rectal cancers are dMMR or MSI-H. The FDA estimates that these biomarkers are found in approximately 3% of locally advanced rectal cancers. That means the approval may be highly meaningful for eligible patients, but it will not apply to most people diagnosed with locally advanced rectal cancer.

What dMMR and MSI-H mean

The terms describe related problems in how tumor cells repair DNA. Normally, mismatch-repair proteins correct copying mistakes. When that repair system is deficient, errors build up. MSI-H refers to a high level of instability in short, repeated sections of DNA.

Doctors can look for these features using methods such as immunohistochemistry, polymerase chain reaction, or next-generation sequencing, depending on the test and clinical setting. Ask whether biomarker testing has already been performed on the biopsy or surgical specimen. If it has, the oncology team can explain which test was used and what the result means.

What the clinical evidence shows

The FDA’s decision relied primarily on interim results from AZUR-1, a phase 2, open-label, single-arm study involving 154 patients with previously untreated dMMR or MSI-H stage II or III locally advanced rectal cancer.

Participants received 500 milligrams of Jemperli by intravenous infusion every three weeks for up to nine cycles, or about six months, unless the cancer progressed or side effects became unacceptable. Patients were assessed with a combination of endoscopy, rectal MRI, and CT scans.

An earlier investigator-led study of 50 patients also produced encouraging results. The FDA reported a 93% 12-month clinical complete-response rate in that study, although it was smaller and had a different design. Of 27 patients followed for at least three years, one had a local recurrence.

Those numbers are promising, but they do not prove that every eligible patient will be cured or avoid later treatment. The AZUR-1 study was single-arm, meaning it did not compare Jemperli directly with standard treatment in a randomized control group. Longer follow-up is also needed to show how durable the responses are and how often cancer returns over time.

Does this mean patients can skip chemotherapy, radiation, or surgery?

Not automatically. The FDA describes Jemperli as an option that may allow some eligible patients to avoid additional treatment, not as a universal replacement for the standard rectal-cancer care pathway.

Patients who achieve a clinical complete response may enter a non-operative management program with intensive surveillance. The FDA describes regular multimodal assessments every four months during the first two years and every six months afterward. That monitoring can include examinations, endoscopy, MRI, and CT imaging.

If the tumor does not fully respond, grows, or returns, the care team may recommend surgery, radiation, chemotherapy, or another treatment plan. Even when surgery is initially avoided, patients need to understand that treatment may still become necessary later.

The decision also depends on factors that a headline cannot capture, including tumor location, imaging findings, symptoms, overall health, fertility goals, ability to attend frequent follow-up visits, and the experience of the cancer center with non-operative management.

Side effects and safety concerns

Jemperli can activate the immune system against healthy organs as well as cancer. Immune-mediated reactions can be serious or life-threatening and may affect organs such as the lungs, intestines, liver, kidneys, skin, hormone-producing glands, or nervous system.

In patients treated for this rectal-cancer indication, the most common side effects reported in at least 15% of patients were:

• Fatigue
• Rash
• Diarrhea
• Itching

The prescribing information also includes warnings about infusion-related reactions, complications involving allogeneic stem-cell transplantation, and harm to an embryo or fetus. Patients who are pregnant, planning pregnancy, or breastfeeding should discuss the risks and recommended precautions with their oncology team.

New or worsening symptoms should be reported promptly. Do not assume that diarrhea, shortness of breath, a rash, unusual weakness, or changes in hormone-related symptoms are minor, because immune-related side effects can worsen without treatment.

What accelerated approval means

Accelerated approval allows the FDA to authorize a medicine based on an earlier measure that is reasonably likely to predict clinical benefit, while additional studies continue. For Jemperli, the agency is requiring ongoing follow-up to determine whether the responses translate into lasting benefits for patients.

That distinction matters. The approval is a real FDA authorization, but the long-term evidence is still developing. Patients and families should ask whether their care plan includes a formal surveillance protocol and what would happen if the cancer shows signs of returning.

Questions to ask an oncology team

• Has my tumor been tested for dMMR or MSI-H, and which test was used?
• Does my diagnosis match the FDA-approved population for Jemperli?
• What are the potential benefits and risks compared with chemotherapy, radiation, and surgery?
• How will you determine whether I have a complete clinical response?
• How often would I need MRI scans, CT scans, endoscopy, and physical examinations?
• What symptoms should lead me to call the oncology team immediately?
• If the cancer does not respond completely or comes back, what treatment would be next?

What U.S. and Canadian patients should know

The October 19, 2026 action is a U.S. FDA approval. The FDA said that regulatory reviews by Health Canada and other international agencies were ongoing at the time of its announcement. Canadian patients should not assume that this U.S. approval automatically means Jemperli is authorized, publicly funded, or routinely available in Canada.

Patients in Canada should ask their oncologist about the current Health Canada status, clinical-trial options, and whether an equivalent treatment pathway is available through their provincial cancer system. Patients in the United States should ask whether their cancer center offers the required biomarker testing and the close surveillance needed for non-operative management.

Helpful Links

• FDA approval details for Jemperli in locally advanced rectal cancer – Review the FDA indication, eligibility criteria, dosing, study results, monitoring approach, and safety warnings.
• FDA news release on Jemperli and rectal cancer – Read the FDA's plain-language announcement about the October 19, 2026 accelerated approval.
• FDA accelerated approval information – Learn how accelerated approval works and why additional studies may be required after authorization.
• FDA verified clinical benefit information – Review the FDA's information about cancer medicines approved through the accelerated-approval pathway.

Frequently Asked Questions

Q. Is Jemperli now approved for all rectal cancer patients?

A. No. The October 19, 2026 FDA approval is limited to adults with previously untreated stage II or stage III locally advanced rectal cancer whose tumors are dMMR or MSI-H. Patients must also have testing performed with an FDA-authorized test.

Q. Can Jemperli eliminate the need for rectal-cancer surgery?

A. It may allow some eligible patients to avoid surgery initially, but that is not guaranteed. Patients who respond completely need intensive surveillance, and surgery or other standard treatment may still be recommended if the cancer does not respond or later returns.

Q. How is dMMR or MSI-H status found?

A. A pathology laboratory can test tumor tissue using methods such as immunohistochemistry, PCR, or next-generation sequencing. Ask the oncology team whether testing was already completed and whether the result meets the FDA-approved criteria.

Q. Is Jemperli approved for this use in Canada?

A. The FDA approval is a U.S. regulatory action. In its October 19, 2026 announcement, the FDA said the Health Canada review was ongoing, so Canadian patients should not assume that the same indication is authorized or publicly funded in Canada.