Cost-effectiveness of chemotherapy and dostarlimab for advanced or recurrent endometrial cancer.

OBJECTIVE:The combination of dostarlimab with carboplatin and paclitaxel has demonstrated improved progression-free survival (PFS) and overall survival (OS) in primary advanced and recurrent endometrial cancer (EC). However, prior studies have not found immunotherapy to be cost-effective, or cost-effective only in specific subgroups, of recurrent endometrial cancer. This study aimed to determine the cost-effectiveness of combination therapy compared to chemotherapy alone. METHOD:A partitioned survival model was developed to compare the cost and effectiveness of dostarlimab in combination with chemotherapy compared to chemotherapy alone in primary advanced or recurrent endometrial cancer. Clinical data was derived from the RUBY trial and drug costs from average sale prices. The incremental cost-effectiveness ratio (ICER) was compared to a set willingness to pay (WTP) of $100,000/QALY to determine cost-effectiveness. One-way and probabilistic sensitivity analyses were performed. RESULTS:In the intention-to-treat (ITT) population, the dostarlimab combination incurred an additional cost of $308,430 but provided an additional 5.67 QALYs compared to chemotherapy alone. The ICER was $54,406/QALY. The dostarlimab combination was cost-effective compared to chemotherapy alone irrespective of MMR expression, with an ICER of $32,287/QALY for MMR deficient (MMRd) EC and $85,744/QALY for MMR proficient (MMRp) EC. Probabilistic sensitivity analysis demonstrated that the combination was cost-effective in 98.2% of iterations at the current WTP threshold. CONCLUSIONS:Despite the higher cost, adding dostarlimab to platinum chemotherapy significantly improves QALYs, rendering this regimen cost-effective relative to chemotherapy alone for treating primary advanced or recurrent EC. Combination therapy is a cost-effective approach for this patient population compared to chemotherapy alone.