The FDA has granted accelerated approval to dostarlimab (Jemperli) for certain patients with operable rectal cancer, marking a shift away from the standard sequence of chemotherapy, radiation, and surgery. The approval covers stage II/III tumors that are mismatch repair-deficient or microsatellite instability-high (dMMR/MSI-H), a biomarker-defined group representing roughly 3% of locally advanced rectal cancers.
Support came from the AZUR-1 trial, in which most evaluable patients achieved a complete response and avoided surgery for at least a year. After a median follow-up of more than two years, no recurrences were reported. However, the FDA notes that long-term relapse risk is unknown, and the indication may be withdrawn if a confirmatory trial does not verify clinical benefit.
Adverse events were mostly mild to moderate, with fatigue, rash, diarrhea, and pruritus most common. A few grade 3 events occurred, including one case each of diabetes, lung infection, hypothyroidism, encephalitis, and neutropenia, plus one grade 4 febrile neutropenia. Dostarlimab already has approvals in endometrial cancer and previously treated dMMR solid tumors.
This article is based on a single source, so there are no differing viewpoints to compare. The source quotes FDA and GSK officials describing the approval as a groundbreaking option that could spare patients the life-changing effects of conventional rectal cancer treatment.