Introduction/Background Novel therapies are being investigated for first-line use in recurrent or advanced endometrial cancer (aEC) patients in Europe, however, country-specific real-world treatment patterns with conventional treatments are not well documented.

Methodology Endometrial Cancer Health Outcomes-Europe-First-Line (ECHO-EU-1L) is a retrospective chart review study in recurrent or aEC patients in United Kingdom (UK), France (FR), Germany (GE), Italy (IT), and Spain (SP). Physicians extracted de-identified data from medical records of adult female patients initiating first-line therapy between 1/JUL/2016 and 31/MAR/2020 after aEC diagnosis. Ethics approval and informed consent waivers were obtained.

Results Overall, 57 physicians provided data for 242 patients (UK=49, FR=49, GE=48, IT=48, SP=48) with a median age of 69 years at aEC diagnosis, 49.2% with endometroid carcinoma, and 23.6% with ECOG≥2 at treatment start. Carboplatin-paclitaxel was the most prescribed first-line regimen in all countries (UK=51.0%, FR=79.6%, GE=58.3%, IT=66.7%, SP=81.3%). Second preference varied: cisplatin-paclitaxel in UK (28.6%), cisplatin-5-fluorouracil in FR (6.1%), bevacizumab-carboplatin-paclitaxel in GE (18.8%), carboplatin monotherapy in IT (12.5%), and doxorubicin-liposomal, megestrol acetate, or paclitaxel in SP (4.2% each). Overall, physicians prescribed >20 different regimens in first-line. Overall, 95% of patients discontinued first-line treatment, mostly due to progression (cross-country range: 40.0–59.2%), regimen completion (26.7–49.0%), and maximum clinical benefit reached (6.1–35.6%). Median time to discontinuation was 5.2 months (95% confidence interval: 4.9–5.5) (UK=4.3, FR=5.4, GE=5.5, IT=6.3, SP=5.3). Overall, 31.3–54.2% of patients initiated second-line treatment.

Conclusion In European recurrent or aEC patients prior to 2021, guideline-recommended carboplatin-paclitaxel was a prevalent first-line regimen, however there were marked cross-country variations in other regimens selected and overall treatment approach. Novel therapies are needed to help streamline treatment options for these patients.

Disclosures Funding for this research was provided by Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA and Eisai Inc., Nutley, NJ, USA. Sneha Kelkar and Yoscar Ogando are employees of OPEN Health, Bethesda, MD, USA, who were paid consultants of Merck Sharp & Dohme LLC a subsidiary of Merck & Co., Inc., Rahway, NJ, USA. in connection with the development of this abstract, study design, management, and statistical analysis for the study. Vimalanand Prabhu and spouse are employees of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, and shareholder of Merck & Co., Inc., Rahway, NJ, USA. Jingchuan Zhang is an employee of Eisai Inc., Nutley, NJ, USA. Véronique Grall is an employee of M3 (EU), Abingdon, England, a subcontractor to OPEN Health, who were paid consultants of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA in the data collection for the study. Christian Marth is an employee of Medical University Innsbruck, Innsbruck, Austria, which has received funding for clinical research support from Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, and reports honoraria/consulting fees from Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.