GSK’s Jemperli approved by FDA for MSI‑H/dMMR stage II–III locally advanced rectal cancer

Regulatory approval

The US Food and Drug Administration granted accelerated approval to Jemperli (dostarlimab) for adults with stage II and III MSI‑H/dMMR locally advanced rectal cancer. The sBLA was reviewed under Project Orbis and the application received Fast Track, Breakthrough Therapy, Priority Review and a National Priority Voucher.

AZUR‑1 efficacy

Approval was based on the phase II AZUR‑1 single‑arm trial (n=154) evaluating dostarlimab monotherapy. Investigator‑assessed data showed 68% (98/144; 95% CI: 60%, 76%) achieved clinical complete response sustained at 12 months (cCR12). An exploratory analysis found 76% (110/144; 95% CI: 69%, 83%) had no evidence of cancer one year or more after treatment. Independent central review data continue to mature: 47% (54/116; 95% CI: 37%, 56%) achieved cCR12, and an additional 38 participants progressing to 12‑month follow‑up have already reached clinical complete response. No disease recurrences have been reported among responders after a median follow‑up of more than two years.

Safety and dosing

Patients received nine cycles of dostarlimab over six months (500 mg IV every three weeks). Serious adverse reactions occurred in 20% of patients; the most common adverse reactions (≥15%) were fatigue, rash, diarrhoea and pruritus. Treatment was permanently discontinued because of adverse reactions in 3% of patients.

Next steps

Full AZUR‑1 interim analysis data will be presented at the ESMO Congress in October 2026, and regulatory reviews are ongoing in other Project Orbis participating countries.