A473among advanced ovarian cancer (OC) patients from two large US healthcare claims databases. Methods: The MarketScan Commercial Claims & Medicare (CCMC) and Surveillance, Epidemiology, and End Results-Medicare (SEER-M) databases were used to identify females aged ≥ 18 years diagnosed with advanced OC (including EOC, fallopian tube [FTC] and primary peritoneal cancer [PPC]) and receiving first-line treatment (i.e. the first claim for any chemotherapy within 90 days post-OC diagnosis) between 1/1/2010 and 12/31/2015. Patients were followed from their initial diagnosis of OC (i.e. index date) until death, loss-to-follow-up or end-of-study period to assess and compare their clinical characteristics and treatment patterns. Results: A total of 7,825 advanced OC patients were identified (N= 6,170 in CCMC, N= 1,655 in SEER-M). Majority of patients were diagnosed with EOC (CCMC: 89%, SEER-M: 80%), and the mean age (SD) at diagnosis was 59 (11) and 75 (6) years, respectively. The median follow-up time was 1.4 and 2.3 years, respectively. Staging information was only available for the SEER-M cohort; 65% of patients were diagnosed with stage III or IV disease. The mean (SD) time from index to initiation of first-line treatment was 35 (20) days in the CCMC cohort and 51 ( 19) days in the SEER-M cohort. Advanced OC patients most frequently received platinum-/taxane-based regimens, with carboplatin/paclitaxel used in 63% and 67% of patients, respectively. Bevacizumabcontaining regimens were utilized in 7% of CCMC OC patients and 5% of SEER-M OC patients, with bevacizumab/carboplatin/paclitaxel combination being the most common. ConClusions: Results: suggest that platinum-containing chemotherapy remains the standard-of-care for advanced OC patients in the US. Despite differences in age between the two OC cohorts, similar treatment patterns were observed.