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. Based on the AZUR-1 trial, 68% of evaluable patients achieved a sustained clinical complete response at one year. The approval could allow eligible patients 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 or III locally advanced rectal cancer that is microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) — a biomarker-defined subgroup representing 5%–10% of rectal tumors. This marks the first immunotherapy approval specifically for this patient population, and eligibility must be confirmed via an FDA-authorized test.
The approval was based on data from the single-arm, phase 2 AZUR-1 trial (n = 154), in which patients received 500 mg of dostarlimab IV every 3 weeks for up to nine cycles. Supporting data also came from an earlier investigator-led phase 2 trial (n = 50), where the cCR12 rate reached 93% and the ORR was 100%, with no patients requiring chemoradiation or surgery.
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Why it matters: For decades, standard treatment for locally advanced rectal cancer meant chemotherapy, radiation, and surgery — a regimen that can cause lasting side effects including sexual dysfunction and infertility. This approval offers a fundamentally different, biology-driven approach that could spare many eligible patients from those burdens entirely.
