Treatment of Unresectable Stage III/IV or Recurrent Endometrial Carcinoma with Mismatch Repair Deficient (MMRd) Tumour

This protocol applies to patients with unresectable stage III or IV, or recurrent endometrial carcinoma whose tumour is confirmed mismatch repair deficient (MMRd), and who have not received prior systemic chemotherapy — except in the adjuvant setting.

MMR deficiency status is the central biomarker driving treatment selection in this population. Establishing MMRd status before initiating therapy is essential, as it directly defines eligibility for the immune checkpoint inhibitor-based approach in this protocol.

For MMRd tumours, current evidence supports an immune checkpoint inhibitor used in combination with chemotherapy, followed by a continuation phase with the checkpoint inhibitor. The full protocol specifies which agents, in what sequence, and under what conditions — details are available below.