Real World Outcomes in Patients With Recurrent, Advanced, or Metastatic Endometrial Cancer Treated With Lenvatinib Plus Pembrolizumab.

Aims: Patients with endometrial cancer who progress following first line therapy have improved survival outcomes with pembrolizumab and lenvatinib (pem/len) compared with standard of care chemotherapy, as demonstrated in KEYNOTE-775. This was in a group of trial patients with good performance status and excluded those with carcinosarcoma histology. In KEYNOTE-775 pem/len was associated with significant toxicity, leading to dose reductions, treatment cessation, and patient morbidity. We set out to assess the tolerability, toxicity and outcomes following pem/len for patients with recurrent, advanced or metastatic endometrial cancer in a real-world setting.

Materials And Methods: UK centres treating patients with pem/len for advanced endometrial cancer within the compassionate access programme were approached. Retrospective data were analysed for those treated between May 2022 and June 2023. Data on patient demographics, treatment, toxicity and outcomes were extracted from medical records. Toxicity and tolerability were compared in those over and under the age of 70.

Results: Seven centres returned data for 70 patients. Median age of patients was 68.5 years (range 45-85) with a performance status of 0-1 in 77.1% and of 2 in 22.9%. Histological subtypes included serous (34.3%), endometrioid (32.9%), carcinosarcoma (14.3%), clear cell (7.1%), mixed (2.9%) and other (8.6%). Grade ≥3 toxicity was reported in 55.7% with any-grade toxicity observed in 85.7%. In those aged ≥70 years (n = 30) the rate of grade ≥3 toxicity was 60.0%. Rates of dose reduction of lenvatinib were 64.3%, and toxicity-related treatment interruption was 45.7%. The 6-month progression-free and overall survival rates were 54.0% (95%CI: 39.0-66.8) and 70.1% (95%CI:56.5-80.1) respectively.

Conclusion: This real-world, observational study of pem/len showed comparable tolerability, toxicity, and outcomes to previously reported clinical trial data. Our cohort included patients with a poorer PS and a broader range of histological subtypes including carcinosarcoma.