GSK's Jemperli Wins FDA Accelerated Approval as First Immunotherapy for Locally Advanced Rectal Cancer

GSK plc (GSK) said the U.S. FDA granted accelerated approval to Jemperli (dostarlimab) as the first and only immunotherapy for adults with stage II and III microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) locally advanced rectal cancer. The approval is based on the Phase II AZUR-1 trial, in which investigator-assessed data showed 68% of evaluable patients (98 of 144) achieved a sustained clinical complete response at 12 months without surgery. In an exploratory analysis, 76% of evaluable patients had no evidence of cancer one year or more after treatment. No disease recurrences were observed among responders after a median follow-up of more than two years. Serious adverse reactions occurred in 20% of patients; fatigue, rash, diarrhea and itching were most common, and 3% discontinued treatment permanently due to adverse events. MSI-H/dMMR biomarkers appear in roughly 5% to 10% of rectal cancers. Full interim AZUR-1 results will be presented at the ESMO Congress in October 2026. GSK closed Monday's trading at $49.46, down 0.10%.