Table 1  Study characteristics and results of the ENGOT-EN-6-NSGO/GOG-3031/RUBY and NRG-GY018 trials.

	ENGOT-EN-6-NSGO/GOG-3031/RUBY	NRG-GY018
EC = endometrial cancer; FIGO = Fédération Internationale de Gynécologie et dʼObstétrique; CHXT = chemotherapy; AUC = area under the curve; C = carboplatin; P = paclitaxel; AE = adverse event; HR = hazard ratio; CI = confidence interval; dMMR = mismatch repair deficiency; MSI = microsatellite instability; pMMR = MMR proficiency
Patients	n = 494	n = 816 (n = 591 [pMMR]; n = 225 [dMMR])
Inclusion criteria	EC FIGO stage III or IV or EC recurrence; for stage IIIA, IIIB, IIIC1 disease: measurable postoperative lesion required (exception: histological findings of serous EC, clear-cell EC or carcinosarcoma); EC stage IIIC2 or IV: no measurable lesion required; EC recurrence: minimum of 6 months after adjuvant CHXT	EC FIGO stage III or IV or first recurrence of EC; for stage III, IVA disease: measurable postoperative lesion required; all histological subtypes except carcinosarcoma; EC recurrence: minimum of 12 months after adjuvant CHXT
Therapy regimen	6 × C (AUC5) and P (175 mg/m 2 ) d1, q21 versus 6 × C (AUC5) and P (175 mg/m 2 ) d1, q21 and dostarlimab 500 mg IV d1, q21 during CHXT and 1000 mg IV d1, q42 for up to 3 years	6 × C (AUC5) and P (175 mg/m 2 ) d1, q21 versus 6 × C (AUC5) and P (175 mg/m 2 ) d1, q21 and pembrolizumab 200 mg IV d1, q21 during CHXT and 400 mg IV d1, q42 until death/progression/unacceptable toxicity or for up to 2 years
Toxicity	2 deaths possibly in connection with dostarlimab (2/241; 0.8%); most common AEs: nausea (+ 8% compared to placebo), alopecia (+ 3%), fatigue (+ 3%), skin rash (+ 9%), hypothyroidism (+ 9%), elevated liver function parameters (+ 5%); discontinuation of therapy with dostarlimab: 17%	1 death (1/112; 0.8%) in the dMMR cohort and 6 deaths (6/295; 2%) in the pMMR cohort; of these, 1 case with possible connection to pembrolizumab; grade 3 AEs > 1%: infusion reactions (3.7%), pneumonitis (1.8%), renal insufficiency (1.8%)
Progression-free survival	After 24 months: 36% (dostarlimab) versus 18% (standard arm); HR 0.64; 95% CI: 0.51 – 0.80; p < 0.001 dMMR/MSI-high subgroup after 24 months: 61% (dostarlimab) versus 15% (standard arm); HR 0.28; 95% CI: 0.16 – 0.50; p < 0.001	After 12 months in the dMMR cohort: risk of progression: 38% (pembrolizumab) versus 74% (standard arm); HR 0.30; 95% CI: 0.19 – 0.48; p < 0.001 After 7.9 months in the pMMR cohort: mean duration of progression-free survival: 13.1 months (pembrolizumab) compared to 8.7 months (standard arm); HR 0.54; 95% CI: 0.41 – 0.71; p < 0.001
Overall survival	After 24 months: 71% (dostarlimab) versus 56% (standard arm); HR 0.64; 95% CI: 0.46 – 0.87; p = 0.0021 dMMR/MSI-high subgroup after 24 months: 83% (dostarlimab) compared to 58% (standard arm); HR 0.30; 95% CI: 0.13 – 0.70	No data