Budget impact of dostarlimab plus carboplatin-paclitaxel for primary advanced or recurrent endometrial cancer from a third-party US payer perspective.

Aim: Dostarlimab plus carboplatin-paclitaxel (CP) significantly increased progression-free survival in patients with primary advanced or recurrent endometrial cancer (pA/rEC) vs CP alone in the RUBY trial (NCT03981796). This analysis estimated the per-member-per-month (PMPM) costs of introducing dostarlimab + CP as a treatment alternative from a third-party US payer perspective.

Materials And Methods: A budget impact model was developed to estimate the costs of introducing dostarlimab + CP into commercial and Medicare health plans over a 3-year time horizon (2023-2025). Costs were sourced from relevant literature and US-specific databases and were calculated using epidemiology data, clinical inputs, treatment costs, and market share estimates. Clinical inputs were sourced from primary clinical trials for each respective treatment (i.e. dostarlimab + CP, CP, pembrolizumab, pembrolizumab plus lenvatinib, bevacizumab + CP, and pembrolizumab + CP). Current and future market shares assumed dostarlimab + CP reduced the market share of CP only. Analyses were performed in mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) and overall populations using a US 2023 cost year.

Results: For a commercial plan, the model estimated (dMMR/MSI-H and overall populations) that 7 and 26 patients would be treated with dostarlimab + CP, respectively; average annual budget impacts per patient treated were $118,257 and $116,094; average budget impacts per patient treated per month (PPPM) were $9,855 and $9,675; average budget impacts PMPM were $0.02 and $0.06. For a Medicare plan, the model estimated that 28 and 93 patients, respectively, would be treated with dostarlimab + CP. Average annual budget impacts per patient treated and PPPM were the same as those for the commercial plan in both populations; average budget impacts PMPM were $0.07 and $0.22, respectively.

Conclusions: Introducing dostarlimab + CP as a first-line treatment for patients with pA/rEC results in minimal budget impact PMPM from a US third-party payer's perspective. Together with the efficacy and safety results from RUBY, these results support the use of dostarlimab + CP as a treatment option.