FDA Approves Jemperli for dMMR Locally Advanced Rectal Cancer

A Rectal Cancer Diagnosis Usually Means Surgery. For Some Patients, That May Now Change

For most people with locally advanced rectal cancer, the standard path has been tough: chemotherapy and radiation, then an operation to remove the rectum. Many patients end up with a temporary or permanent stoma, and some live with bowel, bladder or sexual problems afterwards.

This new approval is about a small group of patients whose tumours have a specific feature called mismatch repair deficiency. For them, an immunotherapy drip given every three weeks may clear the tumour well enough that surgery is not needed at all. It does not apply to every rectal cancer, and it is not a guarantee. But for families facing this diagnosis, it is worth asking the oncologist one simple question: has the tumour been tested for dMMR or MSI-H? If the answer points to dostarlimab, patients in India can get it through a Named Patient Program on a doctor's prescription.

Jemperli Rectal Cancer Approval at a Glance

What the FDA Actually Approved

The approval covers adults whose rectal cancer has not been treated yet, has not spread to distant organs, and tests positive for MSI-H or dMMR. Dostarlimab is a PD-1 blocker. In plain words, it takes the brakes off the immune system so that T-cells can recognise and attack the cancer.

Tumours with mismatch repair deficiency carry a very large number of DNA errors. That makes them look "foreign" to the immune system, which is why they tend to respond so strongly to this kind of drug.

Because this is an accelerated approval, it is based on response data. GSK will need to keep showing benefit in follow-up studies for the approval to stay in place.

What the Trials Showed

AZUR-1: the main study

All 154 patients received dostarlimab 500 mg every three weeks for nine cycles. Doctors then checked the tumour with endoscopy, rectal MRI and CT scans. Patients whose tumour had completely disappeared on these tests were not sent for surgery. Instead, they were watched closely, with checks every 4 months for the first two years.

How patients were managed

• 110 patients (71%) had dostarlimab alone, no other treatment, and no disease progression
• 26 patients (17%) went on to have surgery
• 13 patients (8%) received extra chemotherapy or radiation
• 1 patient had disease progression without further treatment
• 4 patients withdrew or were lost to follow-up

Response numbers

• Overall response rate by independent review: 79%
• Complete response that lasted at least 12 months (cCR12), independent review: 47% of 116 evaluable patients
• Another 33% had a complete response but less than 12 months of follow-up when the data were cut
• Per the trial investigators, cCR12 was 68% and the response rate was 82%
• After a median follow-up of 26.3 months, no patient with a complete or near-complete response had seen the cancer progress

The earlier Memorial Sloan Kettering study

This is the study that made headlines in 2022, when the first patients' tumours vanished on dostarlimab. The FDA reviewed its updated results too. In 50 patients, the response rate was 100% and the 12-month complete response rate was 93%. None of them needed chemoradiation or surgery for their rectal cancer. Among 27 patients followed for at least three years, one had a local recurrence, which was treated.

Side Effects and Warnings to Know

Immunotherapy is not side-effect free. The prescribing information lists warnings for:

• Immune-mediated reactions, where the immune system attacks healthy organs such as the lungs, bowel, liver, hormone glands, kidneys or skin
• Infusion-related reactions during the drip
• Complications after a donor (allogeneic) stem cell transplant
• Harm to an unborn baby, so effective contraception is needed

Tell your doctor straight away about new cough, breathlessness, diarrhoea, yellowing of the skin, severe tiredness or a rash during treatment.

What This Means for Patients in India

The first step is testing. An MMR test (immunohistochemistry) or an MSI test can be done on the biopsy sample that was already taken for diagnosis, so you usually do not need a new procedure. If the result is dMMR or MSI-H, your oncologist can discuss whether dostarlimab-first treatment is suitable.

Jemperli was already approved in the US for some endometrial cancers and for dMMR solid tumours that have come back. If your doctor prescribes it, the Jemperli page on NPP explains how it can be imported for a named patient, with the required paperwork.

Frequently Asked Questions

Does this mean rectal cancer can now be treated without surgery?

Only for some patients. The approval is limited to Stage II/III rectal cancer that is dMMR or MSI-H. In AZUR-1, 71% of patients avoided surgery, radiation and chemotherapy, but 17% still needed an operation. Close follow-up with scans and endoscopy is essential.

How do I know if my rectal cancer is dMMR or MSI-H?

Ask your oncologist or pathologist for an MMR (IHC) or MSI test on your tumour biopsy. It is done on the tissue that was already taken for diagnosis. Your report may also mention other markers, such as BRAF; our guide to BRAF-mutated colorectal cancer explains what that result means.

How long is the treatment?

Dostarlimab is given as a 500 mg infusion every three weeks for up to nine cycles, which is roughly six months.

Is Jemperli available in India?

Jemperli can be accessed in India through a regulated Named Patient Program when a treating doctor prescribes it. Our team helps with the documents and import permission.

Why get it through NPP and not any online seller?

Dostarlimab is a biologic that must be kept cold all the way to the hospital. Unregulated sellers can supply fake, expired or badly stored vials that look exactly like the real thing. Through NPP, the medicine comes from verified sources with proper import approval and cold-chain records.

Talk to Our Team

If you or a family member has dMMR or MSI-H rectal cancer and your oncologist is considering dostarlimab, send us an enquiry. We will explain the process, timelines and documents in simple terms.

Last reviewed: 23 October 2026. This news update is for information only and is not medical advice. Treatment decisions should be made with a qualified oncologist.

References

1. US FDA: FDA grants accelerated approval to dostarlimab for locally advanced rectal cancer (19 Oct 2026)
2. ClinicalTrials.gov: AZUR-1, dostarlimab in untreated dMMR/MSI-H locally advanced rectal cancer (NCT05723562)
3. ClinicalTrials.gov: Memorial Sloan Kettering study of PD-1 blockade in mismatch repair deficient tumours (NCT04165772)
4. Cercek A, et al. PD-1 Blockade in Mismatch Repair-Deficient, Locally Advanced Rectal Cancer. N Engl J Med 2022
5. DailyMed: Jemperli (dostarlimab) prescribing information, GSK