GSK's Jemperli meets main goal in mid-stage rectal cancer trial

GSK said on Monday its cancer drug Jemperli met the primary goal of a mid-stage trial, with a clinically significant rate of patients showing no detectable signs of cancer for one year or more after treatment for a specific type of locally advanced rectal cancer.

Here are some details:

• Dostarlimab, marketed as Jemperli, is being tested in rectal cancer tumours that cannot properly repair DNA damage, a subtype affecting 5%-10% of 730,000 annual global cases, according to GSK.

• Current standard of care typically includes chemotherapy, radiation and surgery, and can lead to lifelong colostomy bag use and infertility.

• These tumours have a genetic characteristic where they cannot properly repair DNA damage, causing mutations to accumulate and making them highly responsive to immunotherapies like Jemperli.

• The interim data from the phase II AZUR-1 trial also showed dostarlimab's safety and tolerability profile was consistent with previous studies in solid tumours.

• Jemperli, already approved in the U.S. and UK for specific endometrial cancer subtypes, generated sales of $1.1 billion in 2025, and GSK expects it to be an important contributor to its long-term sales target of more than £40 billion ($53.52 billion) by 2031.

• The drug has received both Breakthrough Therapy and Fast Track designations from the U.S. Food and Drug Administration, and GSK plans to share data with global regulators for review.

($1 = £0.7474)

(Reporting by Raechel Thankam Job in Bengaluru; Editing by Mrigank Dhaniwala and Eileen Soreng)

Copyright Reuters or USA Today Network via Reuters Connect

This story was originally published July 13, 2026 at 12:15 AM.