FDA grants accelerated approval to Jemperli immunotherapy for a genetically defined type of rectal cancer, offering a path without surgery

On 19 October 2026 the US Food and Drug Administration granted accelerated approval to dostarlimab (Jemperli, GSK), a PD-1 immunotherapy, for adults with stage II or III locally advanced rectal cancer whose tumours are microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR), as determined by an FDA-authorised test. According to GSK, this biomarker is found in roughly 5–10% of rectal cancers.

The evidence

• The decision rests on AZUR-1, a phase II, single-arm, open-label trial in 154 previously untreated patients, who received dostarlimab every three weeks for nine cycles.
• Patients whose tumours disappeared on endoscopy, MRI and CT (a clinical complete response) were not operated on and instead were closely monitored.
• By investigator assessment, 68% (98 of 144) evaluable patients had a sustained clinical complete response at 12 months. In an exploratory analysis, 76% had no evidence of cancer a year or more after treatment. GSK says no recurrences have been reported among responders after a median follow-up of more than two years.
• The trial’s primary endpoint as judged by independent central review is still maturing: so far 47% (54 of 116).

Limitations

This is an accelerated approval based on interim results from a trial without a comparison group, so continued approval may depend on further data confirming lasting benefit. Standard treatment—chemotherapy, radiation and surgery—can cause long-term bowel, urinary and sexual problems and infertility, which is why avoiding it matters to patients. Anyone with rectal cancer should discuss biomarker testing and treatment options with their doctor.