FDA grants Priority Review to GSK’s Jemperli for previously untreated stage II/III dMMR/MSI-H locally advanced rectal cancer, based on AZUR-1 data.
Written By: Rishabh Sonawane, BPharm
Reviewed By: Pharmacally Editorial Team
GSK plc announced on August 24, 2026, that the US Food and Drug Administration (FDA) has accepted its supplemental Biologics License Application (sBLA) for Jemperli (dostarlimab) for previously untreated patients with stage II and III mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) locally advanced rectal cancer.
The FDA has granted the application Priority Review and assigned a PDUFA action date of February 2027. The application is also eligible for expedited review through the Priority Review Voucher program, which could potentially result in an earlier FDA decision. The submission has additionally been accepted under Project Orbis, an FDA Oncology Center of Excellence initiative that supports coordinated reviews by participating international regulatory authorities. Regulatory decisions remain independent in each jurisdiction.
AZUR-1 Provides Registrational Evidence for Jemperli
The regulatory submission is supported by AZUR-1 (NCT05723562), a global, open-label, single-arm, registrational Phase II trial evaluating Jemperli monotherapy in 154 patients with previously untreated stage II and III dMMR/MSI-H locally advanced rectal cancer. Participants received nine cycles of dostarlimab over six months, administered as a 500 mg intravenous infusion every three weeks. The study evaluated sustained clinical complete responses at 12 months (cCR12) to determine whether treatment with dostarlimab alone could allow patients to avoid chemotherapy, radiation, and surgery.
AZUR-1 met its primary objective by demonstrating a meaningful and sustained clinical complete response at 12 months, with no detectable signs of cancer for at least one year in a significant proportion of participants. Interim safety and tolerability findings were consistent with the established safety profile of dostarlimab across solid tumors. GSK plans to present the AZUR-1 data at a scientific congress later in 2026.
Findings Build on Earlier Memorial Sloan Kettering Research
The AZUR-1 findings build on earlier research conducted in collaboration with Memorial Sloan Kettering Cancer Center (MSK), which first demonstrated the potential for dostarlimab to produce clinical complete responses without chemotherapy, radiation, or surgery in patients with dMMR/MSI-H locally advanced rectal cancer (NCT04165772). The AZUR-1 results provide registrational evidence supporting further evaluation of dostarlimab as a potential treatment approach for this biomarker-selected population.
Potential to Reduce the Need for Conventional Treatment
Rectal cancer affects approximately 770,000 people globally each year, with 5–10% estimated to have the dMMR/MSI-H subtype. dMMR/MSI-H tumors have impaired DNA mismatch repair, resulting in an accumulation of mutations that makes them highly responsive to immunotherapies like dostarlimab.
While chemotherapy, radiation, and surgery remain standard treatments for locally advanced rectal cancer, they can cause lasting impacts on bowel, urinary, and sexual function, fertility, and overall quality of life. If approved, dostarlimab could potentially eliminate or delay the need for these conventional treatments in select patients. However, the current application remains under FDA review, and the regimen should not be interpreted as an approved alternative at this stage.
Regulatory Designations and Current Status
Dostarlimab previously received FDA Fast Track and Breakthrough Therapy Designations for this setting. Jemperli is an established component of GSK’s immuno-oncology portfolio, but it is not currently approved anywhere in the world for locally advanced rectal cancer.
Jemperli (dostarlimab) is a programmed death receptor-1 (PD-1)-blocking antibody discovered by AnaptysBio and licensed to TESARO in March 2014. GSK is responsible for the ongoing research, development, commercialization, and manufacturing of Jemperli.
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About the Writer
Rishabha Sonawane, B.Pharm (LinkedIn) is healthcare writer with a strong interest in medical writing, regulatory affairs, clinical research, and AI-driven drug discovery. He has completed specialized training from the NIH and ICMR in clinical pharmacology, clinical research, and scientific writing. Passionate about evidence-based healthcare communication, he focuses on translating complex scientific research into clear, accurate, and engaging medical content.