Dostarlimab + Carbo/Taxol Delays Next Therapy by 11 mo in Front-Line Advanced Endometrial Cancer

Dostarlimab, an anti-PD-1 antibody was combined with carboplatin–paclitaxel (C/P) in the phase 3 RUBY trial (NCT03981796) for 494 patients with advanced or recurrent endometrial cancer (pA/rEC). Compared to placebo + C/P, dostarlimab+ C/P pushed median time to first subsequent therapy to 15.3 mo (vs 10.2 mo; HR 0.63 placebo) and time to second therapy to 31.3 mo (vs 19.9 mo; HR 0.67 placebo); benefit was greatest in dMMR/MSI-H disease where both medians were not reached (HR 0.34/0.41). These durability gains build on RUBY’s earlier PFS edge (12.0 mo for dostarlimab + C/P vs 8.3 mo for placebo + C/P) and compare favorably with pembrolizumab + chemo’s 13.1 mo PFS in the pMMR cohort of KEYNOTE-868, whereas carboplatin-paclitaxel alone typically yields 8–9 mo.