OBJECTIVES: In Study 309/KN-775, treatment with lenvatinib plus pembrolizumab (LEN+PEM) led to significantly longer progression-free and overall survival than treatment of physician’s choice (TPC) among patients with advanced endometrial cancer (EC) following prior platinum-based systemic therapy. We present an analysis of patient-reported EQ-5D from Study 309/KN-775.

METHODS: Patients were randomized 1:1 to receive LEN 20 mg once daily + PEM 200 mg every 3 weeks (n=411) or TPC (doxorubicin 60 mg/m² every 3 weeks or paclitaxel 80 mg/m² weekly for 3 weeks then 1 week off; n=416). EQ-5D-5L was assessed at day 1 of each cycle, at time of discontinuation, and for 4 cycle lengths after discontinuation. EQ-5D-5L responses were converted to UK EQ-5D-3L utility scores. Multivariable linear mixed models were used to estimate the association between EQ-5D and covariates including proximity to death, baseline EQ-5D, and other covariates. Models were selected using the Akaike Information Criterion.

RESULTS: 7,481 complete EQ-5D observations were available. At baseline (n=731), the mean EQ-5D score was 0.75 (standard deviation 0.20). In the selected model, post-progression status and experiencing adverse events (AEs) were independently associated with small decrements (–0.020; p<0.001 and –0.029; p<0.001, respectively). Increasing proximity to death was associated with worsening EQ-5D (–0.216; p<0.001 for 0–28 days from death), with differences beyond 182 days from death not statistically significant. The direct effect for LEN+PEM vs TPC was not statistically significant, however being on treatment (independent of which treatment) was associated with higher EQ-5D than being off treatment (0.084; p<0.001).

CONCLUSIONS: EQ-5D utility scores have not been reported for this patient population. AEs, disease progression, and time to death were associated with significant deteriorations in quality of life in patients with advanced EC following prior platinum-based systemic therapy. These findings will support future economic evaluations of treatments in advanced EC.