The FDA has granted accelerated approval to dostarlimab (Jemperli) — making it the first immunotherapy cleared for adults with stage II/III MSI-H/dMMR locally advanced rectal cancer. Backed by the phase 2 AZUR-1 trial, the PD-1 inhibitor showed a 68% sustained complete response rate at one year. The big win? Eligible patients may be able to skip chemotherapy, radiation, and surgery altogether.
The FDA has granted accelerated approval to dostarlimab (Jemperli, GSK), a PD-1 inhibitor, for adults with stage II/III locally advanced rectal cancer that is microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) — a subset representing about 5–10% of rectal tumors. This marks the first immunotherapy approved specifically for this indication, and it comes with a potentially practice-changing benefit: patients may be able to forgo the standard-of-care trio of chemotherapy, chemoradiation, and surgery.
The approval was supported by the global, single-arm phase 2 AZUR-1 trial (n=154), which showed that 68% of investigator-evaluable patients achieved a sustained clinical complete response at 12 months (cCR12), with no recurrences reported among responders at a median follow-up exceeding 2 years. A supportive investigator-led trial at Memorial Sloan Kettering (n=50) showed even stronger results, with a 93% cCR12 rate and a 100% objective response rate.
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Why it matters: For patients with dMMR/MSI-H rectal cancer, the standard of care has long meant life-altering side effects — bowel dysfunction, bladder issues, sexual dysfunction, and infertility. Dostarlimab's approval opens the door to a biomarker-driven, organ-sparing approach that could fundamentally change how this cancer is treated.
