FDA Approves Immunotherapy That May Let Some Rectal Cancer Patients Skip Surgery and Chemo
The FDA granted accelerated approval to dostarlimab for dMMR/MSI-H rectal cancer. Most trial patients avoided surgery, radiation and chemotherapy.
Summary
The FDA has granted accelerated approval to the immunotherapy Jemperli (dostarlimab-gxly) as a stand-alone treatment for adults with previously untreated stage II or III locally advanced rectal cancer whose tumors have a DNA mismatch repair defect (dMMR or MSI-H). That describes roughly 3% of these cancers. Standard care of chemotherapy, radiation and surgery can damage bowel, urinary and sexual function and fertility, and sometimes requires a permanent colostomy. Jemperli blocks PD-1, a signal tumors use to hide from the immune system. In the phase 2 AZUR-1 study of 154 patients, almost three-fourths had not needed surgery, radiation or chemotherapy after more than two years of median follow-up. An earlier Memorial Sloan Kettering study of 50 patients found no detectable cancer after treatment, and 93% stayed cancer-free for at least 12 months. The approval is accelerated, so longer follow-up must confirm that the benefit lasts.
Detailed Summary
Rectal cancer treatment can save lives, but it can also reshape them. Chemotherapy and radiation before surgery may impair bowel, urinary and sexual function and fertility. Surgery carries risks including poor healing, leaks where the bowel is reconnected, and sometimes a permanent colostomy. Preserving function and quality of life after cancer is a core healthspan concern.
On October 19, 2026, the FDA granted accelerated approval for Jemperli (dostarlimab-gxly) as a single-agent treatment for adults with previously untreated stage II or III locally advanced rectal cancer. At these stages the cancer has grown into nearby tissue or lymph nodes but has not reached distant organs. Eligible tumors must be mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H), as determined by an FDA-authorized test. Published estimates put this subgroup at about 3% of locally advanced rectal cancers.
The biology explains the effect. When the DNA mismatch repair system fails, copying errors accumulate and generate abnormal proteins the immune system can recognize. Jemperli blocks PD-1 on immune cells, removing a shield tumors use to evade immune attack, so these highly mutated tumors are especially vulnerable.
The approval rests on interim results from AZUR-1, a phase 2 study of 154 patients who received up to nine doses every three weeks over six months. After a median follow-up of more than two years, almost three-fourths had not needed surgery, radiotherapy or chemotherapy. An earlier Memorial Sloan Kettering study of 50 patients found no detectable cancer after treatment, and 93% stayed cancer-free for at least 12 months. Only one of the 27 patients followed for at least three years had a recurrence, though the release text is cut off at that point.
For patients, the practical step is testing: tumors need dMMR/MSI-H status confirmed before this option is considered. Caveats matter. The approval is accelerated, follow-up is still short, and the FDA says longer studies are needed to establish how long responses last and how often cancer returns. The trials were single-arm, and only a small subset of patients qualifies. Decisions should be made with an oncology team.
Key Findings
- FDA granted accelerated approval to dostarlimab (Jemperli) alone for untreated stage II/III dMMR or MSI-H locally advanced rectal cancer.
- In AZUR-1 (154 patients), almost three-fourths avoided surgery, radiation and chemotherapy after a median follow-up of over 2 years.
- In a Memorial Sloan Kettering study of 50 patients, none had detectable cancer after treatment; 93% stayed cancer-free for at least 12 months.
- Only about 3% of locally advanced rectal cancers are dMMR/MSI-H, so the option applies to a small subgroup.
- Approval is accelerated; longer follow-up is required to confirm durable responses and recurrence rates.
Methodology
This is an FDA press release reporting a regulatory decision, so it is an official primary source for the approval but not a peer-reviewed analysis. The evidence cited is interim data from the single-arm phase 2 AZUR-1 trial (n=154) and an earlier small Memorial Sloan Kettering study (n=50).
Study Limitations
Follow-up is short, the trials lacked randomized comparison arms, and the durability of response and recurrence rates remain unknown. Only about 3% of patients qualify, and the provided text is truncated before the full long-term recurrence details. Verify the details in the AZUR-1 publications and the full prescribing information.
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