GSK plc announced the US Food and Drug Administration (FDA) accepted the supplemental Biologics License Application (sBLA) for Jemperli (dostarlimab) in combination with standard-of-care chemotherapy (carboplatin and paclitaxel) to expand treatment to all adult patients with primary advanced or recurrent endometrial cancer. This would include patients with mismatch repair proficient (MMRp)/microsatellite stable (MSS) tumours. Currently, Jemperli is FDA-approved in combination with carboplatin and paclitaxel, followed by Jemperli as a single agent for the treatment of adult patients with primary advanced or recurrent endometrial cancer that is either mismatch repair deficient (dMMR), as determined by an FDA-approved test, or microsatellite instability-high (MSI-H).

The FDA granted Priority Review for this application and assigned a Prescription Drug User Fee Act action date of 23 August 2024. The sBLA is based on results from Part 1 of the RUBY phase III trial. The trial met its primary endpoints of investigator-assessed progression-free survival (PFS) and overall survival (OS), demonstrating a statistically significant and clinically meaningful benefit in the overall population of patients treated with dostarlimab plus carboplatin-paclitaxel versus chemotherapy alone.

RUBY Part 1 is the only clinical trial to show a statistically significant survival benefit in the overall patient population. The safety and tolerability analysis from RUBY showed a safety profile for dostarlimab and carboplatin-paclitaxel that was generally consistent with the known safety profiles of the individual agents.