Dostarlimab plus chemotherapy is the only immuno-oncology combination to show statistically significant and clinically meaningful overall survival (OS) in the overall population
31% reduction in risk of death and 16.4-month improvement in median OS observed with dostarlimab plus chemotherapy versus chemotherapy in the overall population
37% reduction in risk of disease progression or death and 6-month improvement in median progression-free survival observed with the addition of Zejula (niraparib) to dostarlimab maintenance following dostarlimab plus chemotherapy versus chemotherapy in MMRp/MSS population where treatment options are still needed
GSK plc (LSE/NYSE: GSK) today announced statistically significant and clinically meaningful overall survival (OS) results from Part 1 and progression-free survival (PFS) results from Part 2 of the RUBY/ENGOT-EN6/GOG3031/NSGO phase III trial in adult patients with primary advanced or recurrent endometrial cancer. These data were presented today in a late-breaking plenary session at the Society of Gynecologic Oncology 2024 Annual Meeting on Women’s Cancer (16-18 March).

The goal of the RUBY phase III trial programme is to evaluate which patients with primary advanced or recurrent endometrial cancer could potentially benefit from treatment with Jemperli (dostarlimab) plus chemotherapy, with or without the addition of Zejula (niraparib) maintenance. Part 1 of the RUBY phase III trial is investigating dostarlimab plus standard-of-care chemotherapy (carboplatin-paclitaxel) followed by dostarlimab compared to chemotherapy plus placebo followed by placebo. Part 2 of the RUBY phase III trial is evaluating dostarlimab plus standard-of-care chemotherapy, followed by dostarlimab plus niraparib as maintenance therapy compared to chemotherapy plus placebo followed by placebo. The safety and tolerability profiles of dostarlimab plus carboplatin-paclitaxel and dostarlimab plus carboplatin-paclitaxel followed by dostarlimab plus niraparib were generally consistent with the known safety profiles of the individual medicines.

Previous data showed a statistically significant and clinically meaningful improvement in PFS with Jemperli plus chemotherapy versus chemotherapy alone in frontline mismatch repair deficient (dMMR)/microsatellite instability-high (MSI-H) primary advanced or recurrent endometrial cancer. These data led to regulatory approvals for this patient population in the US, EU and certain other countries. Data presented today show additional potential benefit of dostarlimab plus chemotherapy, with or without the addition of niraparib, in the overall population of patients with primary advanced or recurrent endometrial cancer, including patients with mismatch repair proficient (MMRp)/microsatellite stable (MSS) tumours, for which there are currently no approved immuno-therapy-based regimens.

Hesham Abdullah, Senior Vice President, Global Head Oncology, R&D, GSK said: “The positive data presented today further show how dostarlimab-based regimens could benefit a broader set of patients with endometrial cancer. The results we’ve seen to date comprise the growing body of evidence supporting the role of dostarlimab as the backbone of our immuno-oncology development programme. Our goal is to continue to identify ways to use dostarlimab alone and in combination with other therapies to help improve outcomes for patients with limited treatment options.”

RUBY Part 1: a statistically significant and clinically meaningful improvement in OS was observed for dostarlimab plus chemotherapy versus placebo plus chemotherapy, meeting a primary endpoint of the study.
Dostarlimab plus chemotherapy versus chemotherapy alone showed:

In the overall population:

a statistically significant reduction in the risk of death by 31% (Hazard Ratio [HR]: 0.69; [95% CI: 0.539–0.890])
a clinically meaningful improvement of 16.4 months in median OS (44.6 months vs 28.2 months)
In a prespecified exploratory analysis of the MMRp/MSS population:

a clinically meaningful trend in reduced risk of death by 21% (HR: 0.79; [95% CI: 0.602–1.044])
a clinically meaningful improvement of seven months in median OS (34.0 months vs 27.0 months)
Full OS summaries are shown below. see & read more on
https://www.gsk.com/en-gb/media/press-releases/positive-ruby-phase-iii-data-show-potential-for-jemperli-dostarlimab-combinations-in-more-patients-with-primary-advanced-or-recurrent-endometrial-cancer/