FDA Approves Jemperli for Rectal Cancer: Some Patients May Avoid Surgery, Radiation and Chemotherapy

MEDISEARCHER NEWS

United States · Rectal cancer · 24 October 2026

The US Food and Drug Administration has approved Jemperli (dostarlimab-gxly) for certain adults with locally advanced rectal cancer, creating a treatment pathway that may allow some eligible patients to avoid chemotherapy, radiation and major rectal surgery.

The accelerated approval, announced on 19 October 2026, applies to adults with previously untreated stage II or stage III locally advanced rectal cancer whose tumors are mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H), as confirmed by an FDA-authorized test.

These biomarkers occur in only a minority of locally advanced rectal cancers, so the approval does not apply to most people diagnosed with the disease. For eligible patients, however, the potential change in treatment is substantial.

What has the FDA approved?

The FDA approved Jemperli as a standalone treatment for adults with previously untreated stage II or III locally advanced rectal cancer that is dMMR or MSI-H.

Jemperli, also known by its generic name dostarlimab-gxly, is an immunotherapy that blocks PD-1, a protein involved in preventing immune cells from attacking other cells.

Some cancers exploit this pathway to shield themselves from the immune system. Blocking PD-1 can allow immune cells to recognize and attack susceptible tumor cells.

dMMR and MSI-H cancers have defects affecting the way DNA-copying errors are repaired. The resulting tumors can accumulate abnormalities that make them particularly susceptible to immune checkpoint therapies such as Jemperli.

Patients must therefore have the appropriate tumor biomarker identified using an FDA-authorized test before being considered for the newly approved treatment.

Could Jemperli really allow patients to avoid rectal cancer surgery?

For some eligible patients, that is the central significance of the approval.

Locally advanced rectal cancer has traditionally been treated using combinations of chemotherapy, radiation and surgery. Although these treatments can be effective against the cancer, they can also have major long-term consequences.

Depending on the treatment and individual patient, these can include changes to bowel function, urinary or sexual problems, fertility effects and complications from surgery. Some patients may require a permanent colostomy.

The new Jemperli approach instead begins with immunotherapy and closely monitors the tumor response.

Patients who achieve a clinical complete response can enter a non-operative management programme rather than automatically proceeding to surgery and other conventional treatment.

This does not mean patients simply finish Jemperli and require no further medical care. Close surveillance is a critical part of the approach because doctors need to identify any recurrence or progression that could require additional treatment.

What did the AZUR-1 trial find?

The FDA based the accelerated approval primarily on interim results from AZUR-1, a multicentre, single-arm Phase II study involving 154 patients with previously untreated stage II or III dMMR/MSI-H locally advanced rectal cancer.

Patients received Jemperli 500 mg intravenously every three weeks for nine treatment cycles, corresponding to approximately six months of therapy.

Of the 154 patients treated:

• 110 patients (71%) received Jemperli alone, did not receive an additional form of cancer treatment and had not experienced disease progression;
• 26 patients (17%) underwent surgery, with or without additional systemic treatment or radiation;
• 13 patients (8%) received additional systemic therapy or radiation;
• one patient experienced progressive disease without further treatment; and
• four patients withdrew or were lost to follow-up.

Among 116 patients who could be evaluated by independent central review, 47% had maintained a clinical complete response for at least 12 months.

Importantly, that figure is still maturing. Another 38 patients had already achieved a clinical complete response but had not yet accumulated the required 12 months of follow-up at the study cutoff.

Investigator assessment produced a higher 12-month sustained complete-response rate of 68% among 144 evaluable patients.

After a median follow-up of 26.3 months, the FDA reported no disease progression among patients assessed as having a complete, sustained complete or near-complete response.

What did the earlier dostarlimab rectal cancer study show?

The FDA also considered an earlier investigator-led study involving 50 patients with the same biomarker-defined form of locally advanced rectal cancer.

In that study, the 12-month sustained clinical complete-response rate was 93%, while the overall response rate was 100%.

No patients received chemoradiation or rectal cancer surgery as part of their treatment for locally advanced rectal cancer.

Among 27 patients followed for at least three years, one experienced a local recurrence. That recurrence was subsequently treated with lymph-node surgery.

The findings were unusually encouraging and helped establish the rationale for the larger AZUR-1 programme, but the relatively small patient numbers and limited duration of long-term follow-up remain important considerations.

Does this mean Jemperli cures rectal cancer?

No. The FDA approval should not be interpreted as evidence that Jemperli is a universal cure for rectal cancer.

First, the treatment applies only to patients whose tumors have the dMMR or MSI-H biomarkers. The FDA estimates that this represents approximately 3% of locally advanced rectal cancers.

Second, the approval was granted through the FDA’s accelerated approval pathway using interim Phase II evidence rather than mature results from a randomized trial comparing long-term survival outcomes.

The results so far show that a substantial proportion of appropriately selected patients can achieve deep responses and potentially avoid conventional treatment. They do not yet establish how durable those responses will be over many years.

The manufacturer must therefore continue following patients to verify the long-term clinical benefit.

What happens after a patient responds to Jemperli?

A patient who achieves a clinical complete response does not simply stop cancer follow-up.

In AZUR-1, tumor response was assessed using a combination of endoscopy, rectal MRI and CT imaging.

Patients entering non-operative management were then monitored using repeated multimodal assessments every four months during the first two years and every six months thereafter.

This surveillance is important because recurrence detected during follow-up may still require surgery, radiation, systemic therapy or another appropriate treatment.

What are the side effects of Jemperli?

Jemperli is an immune checkpoint inhibitor and can cause the immune system to attack healthy tissues as well as cancer cells.

The FDA warns that immune-mediated reactions can affect organs and tissues throughout the body and can sometimes be severe or fatal.

Among patients treated for this form of rectal cancer, commonly reported adverse reactions included fatigue, rash, diarrhea and itching.

Other warnings associated with Jemperli include infusion-related reactions, complications in patients undergoing certain stem-cell transplants and potential harm to an unborn baby.

Treatment therefore requires specialist oncology supervision and appropriate monitoring.

How is Jemperli given for locally advanced rectal cancer?

The FDA-recommended regimen for the newly approved indication is 500 mg of Jemperli administered intravenously every three weeks.

Treatment can continue for up to nine cycles unless the cancer progresses or unacceptable toxicity develops.

This is a prescription cancer immunotherapy administered as part of specialist medical care. It is not a medicine that patients can purchase directly from an ordinary online pharmacy.

Why biomarker testing now matters even more

The approval makes identifying dMMR or MSI-H disease particularly important for people newly diagnosed with locally advanced rectal cancer.

Without appropriate tumor testing, a patient who might qualify for the new immunotherapy pathway could potentially go unidentified.

The treatment decision itself remains individual. Tumor characteristics, imaging, general health, treatment response and the ability to undergo intensive long-term surveillance all need to be considered by the patient’s cancer team.

Will Jemperli be approved for rectal cancer outside the US?

The current decision applies to the United States.

However, the application was reviewed through Project Orbis, an FDA Oncology Center of Excellence programme designed to allow participating regulators to review important oncology applications concurrently.

For this Jemperli application, the FDA collaborated with regulators in Canada, the United Kingdom, Switzerland and Israel.

Those regulatory reviews were still ongoing when the FDA announced its approval.

This means the US decision could be followed by additional national approvals, although each regulator makes its own decision and approval in the United States does not guarantee approval elsewhere.

Why this approval matters

The importance of the Jemperli decision goes beyond adding another medicine to the list of available cancer therapies.

For a small but identifiable group of patients, the goal is potentially to treat the cancer effectively while avoiding some of the most life-changing aspects of conventional rectal cancer treatment.

The evidence is not yet mature enough to conclude that immunotherapy can permanently replace chemotherapy, radiation and surgery for every eligible patient.

But the FDA’s decision moves this approach from an experimental strategy into an approved US treatment pathway for appropriately selected patients.

Longer-term follow-up from AZUR-1 will now be particularly important in determining how often complete responses remain durable and how frequently patients eventually require additional treatment.

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Sources and verification

MediSearcher reviewed the following primary and authoritative sources when preparing this article:

• US Food and Drug Administration — FDA grants accelerated approval to dostarlimab for locally advanced rectal cancer
• US Food and Drug Administration — FDA approves immunotherapy that may allow certain patients with rectal cancer to avoid chemotherapy, radiation and surgery
• US Food and Drug Administration — Jemperli supplemental biologics licence application approval letter
• ClinicalTrials.gov — AZUR-1 (NCT05723562)
• ClinicalTrials.gov — dostarlimab in locally advanced dMMR rectal cancer (NCT04165772)

This article is for general informational purposes only and is not medical advice. Cancer treatment decisions depend on individual diagnosis, tumor biomarkers, response to treatment and other clinical factors. Patients should discuss treatment options with their oncology team.