RT Journal Article SR Electronic T1 EPV129/#529 Long-term clinical and economic value of pembrolizumab + lenvatinib compared with chemotherapy in previously treated advanced endometrial cancer patients in Sweden: a cost-effectiveness analysis JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A81 OP A81 DO 10.1136/ijgc-2021-IGCS.199 VO 31 IS Suppl 4 A1 Upadhyay, N A1 Ralph, L A1 Ljungcrantz, C A1 Merchant, A A1 Haycroft, B A1 Fornwall, A A1 Prabhu, V A1 Orlowski, R A1 Duska, L YR 2021 UL http://ijgc.bmj.com/content/31/Suppl_4/A81.2.abstract AB Objectives Advanced endometrial cancer (aEC) patients previously treated with systemic therapy have limited treatment options in Europe. In the Phase-III trial KEYNOTE-775, pembrolizumab + lenvatinib (PEM+LEN) demonstrated statistically significant and clinically meaningful improvements in OS, PFS and ORR versus chemotherapy (the treatment of physician’s choice [TPC] of doxorubicin or paclitaxel). The long-term clinical and economic value of PEM+LEN needs to be understood. The objective of this study was to assess the cost-effectiveness of PEM+LEN vs TPC for previously treated aEC patients in Sweden.Methods A three-state partitioned survival model (progression free, progressed disease, and death) was developed. The proportion of patients in each health state was estimated using the area under the curve based on KN-775 OS and PFS data, to which costs/benefits from a Swedish healthcare perspective were applied over a lifetime horizon. OS, PFS, time-on-treatment, adverse event, and EQ-5D utility data were obtained from KEYNOTE-775. Treatment acquisition, administration, resource use and adverse events cost were obtained from Sweden. A 3% discount rate was applied. Sensitivity analyses were conducted.Results Treatment with PEM+LEN resulted in an increase of 1.96 Life-years (LYs), 1.42 quality-adjusted life-years (QALYs), and SEK 1,180,044 in costs vs chemotherapy (TPC). The incremental cost-effectiveness ratio for PEM+LEN vs chemotherapy was 828,569 SEK/QALY-gained. Cost-effectiveness results were sensitive to OS/time-on-treatment extrapolations, and adjustments for subsequent therapies.Conclusions Model-based analysis suggests that PEM+LEN extends life-years and QALYs over chemotherapy, and can be considered cost-effective compared with chemotherapy at a willingness-to-pay threshold of SEK 1-million in Sweden.