Updated results from the RUBY phase 3 trial suggest that adding the immunotherapy drug dostarlimab to standard chemotherapy may offer the potential for long-term cure in patients with advanced or recurrent dMMR/MSI-H endometrial cancer.
After a median follow-up of 55.6 months, patients receiving dostarlimab plus carboplatin and paclitaxel achieved a 4-year progression-free survival rate of 57.9%, compared with 15.7% for those receiving chemotherapy alone. The 4-year overall survival rate was 72.8% versus 40.3%, respectively, and the median overall survival for the dostarlimab group has not yet been reached.
Using statistical cure modeling, investigators estimated that 54% of patients treated with the dostarlimab combination could potentially be cured, compared with 14% of those receiving chemotherapy alone. Among patients who remained progression-free for two to three years, the likelihood of staying progression-free at four years reached 91.7%.
The trial enrolled 494 patients, including 118 with confirmed dMMR/MSI-H tumors. The findings strengthen evidence that immunotherapy can deliver durable, long-term benefits in this high-risk endometrial cancer population and may shift treatment goals from disease control toward the possibility of cure.