(Bloomberg) -- A GSK Plc drug for endometrial cancer posted strong results in a trial, a sign it could become the top seller the British pharmaceutical giant is predicting.

Jemperli, when combined with chemotherapy, reduced disease progression and the risk of death in 72% of patients who have a specific type of tumor that affects about a third of people with endometrial cancer, GSK said in a statement Monday. It helped 36% of patients overall.

European and US regulators greenlit the use of Jemperli in April 2021 and GSK is planning to apply for another US approval in the first half of the year based on the latest results. GSK has invested heavily in the drug, also known as dostarlimab, and is seeking to eventually show it could be used to treat several types of cancer. 

“We believe the real importance for Jemperli is longer term as it could form the foundations of the future GSK Oncology portfolio,” Shore Capital analyst Sean Conroy wrote in a note. GSK shares were up 0.7% on Tuesday morning. 

This result “adds to the growing body of evidence on dostarlimab, strengthening our belief in its potential to transform cancer treatment as a backbone immuno-oncology therapy,” said Hesham Abdullah, GSK’s global head of oncology development.

Endometrial cancer is found in the inner lining of the uterus and is the most common gynecologic cancer in developed countries. About 15-20% of patients will already have advanced cancer at the time of diagnosis, the company said.

GSK has been trying to replenish its product pipeline in recent years as the company faces pressure to improve shareholder returns and keep up with UK rival AstraZeneca Plc. Last year GSK split from its consumer arm, listing that unit separately, to focus on the pharma and vaccines business.

The company first published headline results from the so-called Ruby trial testing Jemperli with chemo in December. GSK is also testing the drug against rectal cancer.

--With assistance from Lisa Pham.

(Upadtes with analyst comment in fourth paragraph.)

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