OBJECTIVES: With the arrival of immunotherapies as first-line (1L) treatment for advanced or recurrent endometrial cancer (EC), there is concern regarding the cost of adopting these technologies. The aim of this study was to evaluate the budget impact of introducing these new treatment options in patients with EC over 3 years.

METHODS: A cost calculator was developed to estimate the treatment cost of dostarlimab and pembrolizumab. A scenario of 10 new patients per year for each immunotherapy was considered. In the first year, 10 patients were included; from the second year onwards, the prevalence of patients from the previous year who continued the treatment was added to the 10 new patients of the current year. The treatment cost considered the posology of the clinical trials and drug acquisition cost from the official Brazilian list price by the Chamber of Regulation of the Pharmaceutical Market. The progression-free survival (PFS) curve of the intention-to-treat (ITT) population from the RUBY trial (NCT03981796) was used to estimate treatment duration, and it was assumed there were no differences in PFS for both technologies. Only the cost of the immunotherapies was considered in the analysis.

RESULTS: Dostarlimab presented a cost of BRL $4,502,065 (first year); $6,749,168 (second year); and $8,489,471 (third year), accruing a total cost of $19,740,704. Pembrolizumab presented a cost of $5,590,288 (first year); $8,380,552 (second year); and $8,380,552 (third year), accruing a total cost of $22,351,391.

CONCLUSIONS: Despite the significant advancements immunotherapies have brought to various cancer treatments, including for EC, a cost calculator analysis can help payers understand the financial impact of introducing new technologies. The results indicate the potential cost savings with dostarlimab, which presented a lower total cost over 3 years.