OBJECTIVES:

To evaluate cost-effectiveness of pembrolizumab plus lenvatinib for treatment of advanced endometrial carcinoma in women who have progressed following prior systematic therapy and are not candidate for curative surgery or radiation, from the French healthcare system perspective.

METHODS:

A three-state partitioned survival model (pre-progression, post-progression and death) was developed to estimate costs, effectiveness, and incremental cost-effectiveness ratio (ICER) of pembrolizumab + lenvatinib versus chemotherapy (doxorubicin or paclitaxel). Clinical and quality of life data were derived from the phase 3 study KEYNOTE-775. Progression-free survival, overall survival and time on treatment were extrapolated over a 10-year time horizon based on parametric functions. EQ-5D-5L data estimated by a regression model were converted to French population-based utilities using the French value set. Only direct medical costs were considered, based on public sources. Costs and health outcomes were discounted at 2.5% per year. ICER was calculated as cost per quality-adjusted life year (QALY) gained and per life year gained (LYG). Deterministic and probabilistic sensitivity analyses and scenarios analyses were conducted to assess robustness of results.

RESULTS:

The model projected that pembrolizumab + lenvatinib is associated with 1.25 LYG and 1.04 additional QALY versus chemotherapy as well as incremental costs of 131,293 € (discounted). ICERs were 126 246€/QALY and 104 607€/LY respectively. Results were mostly sensitive to parametric survival functions chosen to extrapolate overall survival, with an ICER varying from 107 532€/QALY (-15%) with Log-normal to 144 565€/QALY (+14%) with Weibull. Pembrolizumab plus lenvatinib has more than 80% probability of being cost-effective beyond the willingness-to-pay (WTP) threshold of 160,000€/QALY.

CONCLUSIONS:

Model-based analysis suggests that pembrolizumab + lenvatinib improves life expectancy and is likely to be cost-effective versus chemotherapy for treatment of advanced endometrial carcinoma in women who have progressed following prior systematic therapy and are not candidate for curative surgery or radiation in France, assuming a WTP under 160,000€/QALY.