Introduction/Background In European clinical practice, historically there has been no consensus on the second-line standard of care for recurrent or advanced endometrial cancer (aEC) patients, and differences in real-world treatment patterns with conventional treatments across European countries are not well documented.

Methodology Endometrial Cancer Health Outcomes-Europe (ECHO-EU) is a multicenter, retrospective, chart review study in recurrent or aEC patients across the United Kingdom (UK), France (FR), Germany (GE), Italy (IT), and Spain (SP). Physicians extracted de-identified data from medical records of adult female patients diagnosed with recurrent or aEC who progressed between 1/JUL/2016 - 30/JUN/2019 following prior systemic therapy. Data collected included demographics, clinical characteristics, and treatment patterns. Ethics approval and informed consent waivers were obtained in respective countries.

Results Overall, 103 physicians provided data for 475 patients (UK=101, FR=96, GE=88, IT=100, SP=90) with a median age of 69 years at aEC diagnosis, 57.7% with endometroid carcinoma, and 45.9% with ECOG ≥2 at second-line treatment initiation. In second-line, the use of non-platinum-based chemotherapy varied by country (UK=36.6%, FR=68.8%, GE=46.6%, IT=73.0%, SP=52.2%); other patients received platinum-based chemotherapy (UK=35.6%, FR=10.4%, GE=13.6%, IT=9.0%, SP=21.1%), taxane monotherapy (UK=7.9%, FR=5.2%, GE=10.2%, IT=8.0%, SP=1.1%), or endocrine therapy (UK=6.9%, FR=15.6%, GE=27.3%, IT=10.0%, SP=23.3%). In second-line, physicians prescribed >40 different regimens. Overall, 90.3% of patients discontinued second-line treatment (UK=94.1%, FR=90.6%, GE=92.0%, IT=86.0%, SP=88.9%), primarily due to disease progression (UK=45.3%, FR=70.1%, GE=56.8%, IT=50.0%, SP=63.8%). Median time to discontinuation was 4.9 months (95% confidence interval: 4.5–5.3) (UK=4.2, FR=5.0, GE=4.2, IT=6.0, SP=5.7). Only a small proportion of patients (<10%-20%) initiated third-line therapy.

Conclusion For pre-treated European recurrent or aEC patients prior to mid-2019, our study found no consensus on a standard of care in second-line, substantial differences in treatment regimens across countries, and a high rate of discontinuation. Recently approved novel therapies may streamline treatment options for this patient population.

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. Jingchuan Zhang is an employee of 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. Nicola Miles 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.