FDA Accelerated Approval: Which Patients With Rectal Cancer May Avoid Chemotherapy, Radiation and Surgery?

On October 19, 2026, the U.S. Food and Drug Administration granted accelerated approval to dostarlimab-gxly, marketed as Jemperli, for a new indication in selected adults with previously untreated locally advanced rectal cancer.

The approval drew attention because some eligible patients treated with dostarlimab alone may be able to avoid immediate chemotherapy, radiation and surgery. It is not, however, a treatment option for every person with rectal cancer.

The approval applies to adults with previously untreated Stage II or Stage III locally advanced rectal cancer whose tumors are mismatch repair deficient, known as dMMR, or microsatellite instability-high, known as MSI-H. The biomarker must be confirmed by an FDA-authorized test.

dMMR and MSI-H describe defects in the system cancer cells use to repair errors made while copying DNA. These tumors may accumulate abnormal proteins that make them more recognizable to the immune system and more responsive to PD-1 blockade. The FDA estimates that only about 3% of locally advanced rectal cancers have these biomarkers, so most patients with rectal cancer are outside this approval.

Dostarlimab is a PD-1 inhibitor. PD-1 is a protein on immune cells, and some cancers exploit related signaling to suppress an immune response. Blocking the pathway can help immune cells recognize and attack tumor cells.

A dMMR or MSI-H result alone is not enough to determine whether treatment is appropriate. Cancer stage, pathology, imaging, overall health and the ability to complete intensive surveillance all require evaluation by an experienced multidisciplinary team.

The accelerated approval was based primarily on interim data from AZUR-1, a Phase 2 study of 154 patients with previously untreated Stage II or III dMMR/MSI-H locally advanced rectal cancer. Patients received dostarlimab alone and were assessed with endoscopy, rectal MRI and CT imaging of the chest, abdomen and pelvis.

At the data cutoff, 110 of the 154 treated patients had received dostarlimab alone, had not received another form of treatment and had not experienced disease progression. Among patients evaluable by independent central review, the rate of clinical complete response sustained for at least 12 months was 47%; the corresponding investigator-assessed rate was 68%. The difference underscores the importance of assessment methods, follow-up duration and patients who had not yet reached sufficient follow-up.

The FDA also reviewed an investigator-led, multicenter Phase 2 study involving 50 similar patients. The sustained 12-month clinical complete response rate was 93%, and the objective response rate was 100%. Among 27 patients followed for at least three years, one developed a local recurrence and underwent lymph node removal.

These findings are promising, but both studies were single-arm, open-label trials without a randomized standard-treatment control group. A clinical complete response does not by itself establish a long-term cure. Longer follow-up is needed to assess local recurrence, distant metastasis, organ preservation and survival.

The FDA accelerated approval pathway can make treatments for serious conditions available earlier based on an intermediate endpoint or preliminary evidence that is reasonably likely to predict clinical benefit. It does not mean that every long-term question has been answered, and it differs from a traditional approval supported by mature long-term outcomes.

The sponsor must complete AZUR-1 and further characterize response duration, three-year organ preservation, relapse or metastatic disease and five-year survival. If confirmatory evidence does not verify clinical benefit, the FDA can require changes to or withdrawal of the indication.

For patients who achieve a clinical complete response and enter nonoperative management, care does not simply end. The studies use frequent endoscopy, MRI, CT and other assessments to detect residual disease, recurrence or progression as early as possible. The ability to complete long-term surveillance is an important part of considering an organ-preservation approach.

Patients who do not achieve a complete response, or whose cancer later recurs or progresses, may still need surgery, radiation, chemotherapy or another standard treatment. A news report should not be used as a reason to delay scheduled care or change treatment without professional evaluation.

Patients may ask whether their pathology or molecular testing includes MMR or MSI status, how the biomarker was tested, whether the stage and imaging findings fit the approved indication, and whether the treatment goal is cure, disease control or symptom relief.

When discussing dostarlimab or nonoperative management, it is also important to understand immune-related adverse effects, the definition of a complete response, the surveillance schedule and the plan if the tumor does not respond or later returns. Immunotherapy can cause the immune system to damage normal organs and tissues, sometimes severely, and requires management by an experienced team.

This article summarizes publicly available FDA and clinical research information for general educational purposes. It does not provide diagnosis, treatment, medication or individualized medical advice. Treatment decisions should be made by appropriately qualified oncology professionals based on the patient's circumstances.