Cost-Effectiveness Analysis of Dostarlimab Plus Carboplatin-Paclitaxel in Primary Advanced or Recurrent Endometrial Cancer With Deficient Mismatch Repair (dMMR) and High Microsatellite Instability (MSI-H) in France
Author(s)
Thibaut de la Motte Rouge, MD PhD1, Jean Sébastien Frenel, MD2, Capucine Lachaize, PharmD, MSc3, Guillaume Laubel, PharmD4, Ester Alessandrini, PhD5, Amel Zoubir, MD5, Gaëlle Nachbaur, MSc6, Jérémy CARETTE, PharmD4, Henri Leleu, PhD, MD4.
1Centre Eugène Marquis, Rennes, France, 2Institut de Cancérologie de L’Ouest, Saint-Herblain, France, 3GSK France, Rueil-Malmaison, France, 4Public Health Expertise, Paris, France, 5GSK FRANCE, Rueil-Malmaison, France, 6GSK France, Rueil Malmaison, France.
1Centre Eugène Marquis, Rennes, France, 2Institut de Cancérologie de L’Ouest, Saint-Herblain, France, 3GSK France, Rueil-Malmaison, France, 4Public Health Expertise, Paris, France, 5GSK FRANCE, Rueil-Malmaison, France, 6GSK France, Rueil Malmaison, France.
OBJECTIVES: Deficient mismatch repair (dMMR) and high microsatellite instability (MSI-H) are distinct biological features observed in approximately 15% to 33% of endometrial cancer (EC). Dostarlimab plus carboplatin-paclitaxel (CP) was granted a marketing authorization in December 2023 for the treatment of dMMR/MSI-H primary advanced or recurrent EC (pA/R EC) based on the results of RUBY-part-1 clinical trial. We assessed the cost-effectiveness of dostarlimab plus CP versus CP in this indication according to French HTA requirements.
METHODS: A partitioned survival model (progression-free, post-progression, and death) comparing dostarlimab plus CP versus CP was developed. Results of the RUBY-part-1 study in patients with dMMR/MSI-H pA/R EC were used to estimate progression-free survival (PFS), overall survival (OS), treatment duration, subsequent treatments, and French utilities based on the EQ-5D-5L questionnaire. Base case analysis was defined in accordance with HAS guidelines and resulted in an assessment without major reservation. Sensitivity analyses were explored to measure the impact of structural assumptions.
RESULTS: Over a chosen restrictive 15-year time horizon, dostarlimab + CP resulted in a total QALY gain of 2.45 (+69%) overall and an additional cost of €176,745 compared to CP (ICER=72,256€/QALY). With a time horizon of 20 years, the incremental cost-effectiveness ratio (ICER) would have been decreased by 11%. Less limiting assumptions on survival extrapolations would also reduce the ICER of dostarlimab + CP versus CP (around 10%, for example, when relying on extrapolated OS approach versus assumed loss of efficacy after the end of treatment).
CONCLUSIONS: Despite a strict conservative approach required by the HAS, dostarlimab + CP in dMMR/MSI-H pA/R EC is a cost-effective strategy. This outcome is attributed to the substantial improvement of PFS (HR=0.28) and OS (HR=0.30) in the clinical trial, the maintenance of patients as progression-free that is associated with better utility value, and the reduced subsequent treatment cost.
METHODS: A partitioned survival model (progression-free, post-progression, and death) comparing dostarlimab plus CP versus CP was developed. Results of the RUBY-part-1 study in patients with dMMR/MSI-H pA/R EC were used to estimate progression-free survival (PFS), overall survival (OS), treatment duration, subsequent treatments, and French utilities based on the EQ-5D-5L questionnaire. Base case analysis was defined in accordance with HAS guidelines and resulted in an assessment without major reservation. Sensitivity analyses were explored to measure the impact of structural assumptions.
RESULTS: Over a chosen restrictive 15-year time horizon, dostarlimab + CP resulted in a total QALY gain of 2.45 (+69%) overall and an additional cost of €176,745 compared to CP (ICER=72,256€/QALY). With a time horizon of 20 years, the incremental cost-effectiveness ratio (ICER) would have been decreased by 11%. Less limiting assumptions on survival extrapolations would also reduce the ICER of dostarlimab + CP versus CP (around 10%, for example, when relying on extrapolated OS approach versus assumed loss of efficacy after the end of treatment).
CONCLUSIONS: Despite a strict conservative approach required by the HAS, dostarlimab + CP in dMMR/MSI-H pA/R EC is a cost-effective strategy. This outcome is attributed to the substantial improvement of PFS (HR=0.28) and OS (HR=0.30) in the clinical trial, the maintenance of patients as progression-free that is associated with better utility value, and the reduced subsequent treatment cost.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
EE196
Topic
Economic Evaluation, Health Technology Assessment
Topic Subcategory
Value of Information
Disease
Oncology, Reproductive & Sexual Health