FDA Grants Accelerated Approval to Jemperli for Locally Advanced Rectal Cancer

The FDA has granted accelerated approval to the PD-1–blocking antibody dostarlimab-gxly (Jemperli, GSK) as a single agent for adults with stage II/III locally advanced rectal cancer (LARC) that is microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR), as determined by an FDA-authorized test for solid tumors, GSK announced.

About 5% to 10% of rectal cancers are MSI-H or dMMR, according to GSK. The company said the current standard of treatment for LARC, including chemotherapy, radiation, and surgery, can cause lasting bowel, urinary, and sexual dysfunction, secondary cancers, and infertility.

Approval was based on the global, open-label, single-arm phase 2 AZUR-1 trial of dostarlimab in 154 patients with previously untreated stage II/III MSI-H/dMMR LARC. Patients received 500mg intravenously every three weeks for nine cycles. For the primary endpoint, sustained clinical complete response at 12 months (cCR12) by independent central review, 47% of evaluable patients achieved cCR12 (54/116; 95% CI, 37%-56%). GSK said the trial met its primary objective; these data are still maturing, with 38 more patients in clinical complete response awaiting 12-month follow-up. By investigator assessment, 68% of evaluable patients (98/144) achieved cCR12.

In an exploratory analysis, 76% of evaluable patients (110/144) had no evidence of cancer one year or more after treatment, including 12 with a pathologic complete response after surgery. No recurrences have been reported among responders after a median follow-up of more than two years. Serious adverse reactions occurred in 20% of patients, and 3% permanently discontinued treatment because of adverse reactions. The most common adverse reactions were fatigue (32%), rash (22%), diarrhea (18%), and pruritus (17%).

Dostarlimab received Fast Track and Breakthrough Therapy designations for this indication, and the application received Priority Review. The indication states that the long-term risk of relapse is unknown, and that continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial. GSK said full interim AZUR-1 data will be presented at the European Society for Medical Oncology Congress in October 2026.

Source: GSK. Jemperli (dostarlimab-gxly) approved in US as first and only immunotherapy for adults with MSI-H/dMMR locally advanced rectal cancer. Press release. GSK; October 19, 2026. Accessed October 19, 2026.