Cost-effectiveness of dostarlimab plus carboplatin-paclitaxel for primary advanced or recurrent endometrial cancer from a US payer perspective

Objective: Dostarlimab in combination with carboplatin-paclitaxel (CP) improves progression-free survival in patients with primary advanced or recurrent endometrial cancer (pA/rEC), including in patients whose cancer is mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H). This study examined the cost-effectiveness of dostarlimab plus CP as a first-line treatment in the dMMR/MSI-H and overall populations.

Methods: A partitioned survival model with three mutually exclusive health states (progression-free disease, progressed disease, death) was developed using a US base case and a third-party payer perspective. Clinical data were from the RUBY trial and published sources. Costs were from US databases. The primary outcomes were life-years (LYs), quality-adjusted life-years (QALYs), incremental costs, and incremental cost-effectiveness ratios (ICERs). One-way and probabilistic sensitivity analyses were also performed.

Results: In the dMMR/MSI-H population, the model predicted gains of 6.9 LYs and 5.4 QALYs with dostarlimab plus CP compared with CP; costs were $307,696 higher with dostarlimab plus CP, resulting in an ICER of $57,151 per QALY gained. In the overall population, gains of 2.0 LYs and 1.5 QALYs were predicted with dostarlimab plus CP compared with CP; costs were $215,876 higher, resulting in an ICER of $143,783 per QALY gained. ICERs were most sensitive to the overall survival hazard ratio. At a willingness-to-pay threshold of $150,000, dostarlimab plus CP had cost-effectiveness probabilities of 100 % and 53.7 % in the dMMR/MSI-H and overall populations, respectively.

Conclusions: Dostarlimab plus CP is cost-effective as a treatment for the dMMR/MSI-H and overall populations of US patients with pA/rEC.