Jemperli (dostarlimab-gxly) approved in US as first and only immunotherapy for adults with MSI-H/dMMR locally advanced rectal cancer

• Approval based on AZUR-1 data showing clinically significant proportion of participants with no detectable signs of cancer one year or more after treatment

• No disease recurrences reported among responders after median follow up of more than two years

• Jemperli monotherapy could help eligible patients avoid chemotherapy, radiation and surgery

PHILADELPHIA, October 19, 2026--GSK plc (LSE/NYSE: GSK) today announced the US Food and Drug Administration (FDA) has approved Jemperli (dostarlimab-gxly) as the first and only immunotherapy for adults with stage II and III microsatellite instability-high (MSI-H)/mismatch repair deficient (dMMR) locally advanced rectal cancer under the accelerated approval pathway.

Current standard of treatment for locally advanced rectal cancer includes chemotherapy, radiation and surgery1, but these can have lasting consequences, including bowel, urinary and sexual dysfunction, secondary cancers and infertility2,3. For patients with MSI-H/dMMR tumors, a biomarker found in around 5-10% of rectal cancers4, Jemperli monotherapy could help avoid these interventions.

Tony Wood, Chief Scientific Officer, GSK, said: "Today, Jemperli becomes the first and only approved immunotherapy for adults in the US with MSI-H/dMMR locally advanced rectal cancer. For decades, treatment has relied on chemotherapy, radiation and surgery. This approval offers a new treatment approach and represents an important step towards more personalized care for these patients."

Dr. Andrea Cercek, MD, Principal Investigator of AZUR-1, Section Head of Colorectal Cancer and Co-Director of the Center for Young Onset Colorectal and Gastrointestinal Cancer, Memorial Sloan Kettering Cancer Center, said: "The AZUR-1 results demonstrate the potential for a fundamentally different treatment approach in this biomarker-defined patient population, and today's approval means MSI-H/dMMR patients can now access a licensed treatment tailored to the biology of their disease."

Michael Sapienza, CEO, Colorectal Cancer Alliance, said: "People facing rectal cancer are often thinking not only about treating their disease, but also worrying about what life will look like afterwards. The possibility of avoiding chemotherapy, radiation and surgery represents a meaningful advance for patients and their families. Biomarker testing at diagnosis will be essential to identifying patients who may be eligible for this treatment and helping them understand their options."

Approval was based on data from the phase II AZUR-1 trial. The study met its primary objective, demonstrating a clinically significant proportion of participants achieved sustained clinical complete responses at 12 months (cCR12), with data continuing to mature.