Cost-Effectiveness of Ribociclib Plus Letrozole for Premenopausal Women With HR+/HER2- Advanced Breast Cancer in Thailand: A Societal Perspective
Author(s)
Surachai Sittibodin, Ph.D.candidate1, Onanong Waleekhachonloet, Ph.D.1, Thananan Rattanachotphanit, Ph.D.1, Supon Limwattananon, Ph.D.2, Chulaporn Limwattananon, Ph.D.3.
1Division of Clinical Pharmacy, Faculty of Pharmacy, Mahasarakham University, Mahasarakham, Thailand, 2International Health Policy Foundation, Bangkok, Thailand, 3Independent researcher, Khon Kaen, Thailand.
1Division of Clinical Pharmacy, Faculty of Pharmacy, Mahasarakham University, Mahasarakham, Thailand, 2International Health Policy Foundation, Bangkok, Thailand, 3Independent researcher, Khon Kaen, Thailand.
OBJECTIVES: The MONALEESA-7 trial demonstrated significantly longer progression-free and overall survival with ribociclib plus endocrine therapy for premenopausal women with hormone receptor-positive (HR+), human epidermal receptor 2-negative (HER2-) advanced breast cancer. However, ribociclib is not included in Thailand’s National List of Essential Medicines, and no economic evaluation has been conducted in this population. This study aims to evaluate the cost-effectiveness of ribociclib plus letrozole for premenopausal women with HR+, HER2- advanced breast cancer in Thailand.
METHODS: A Markov model with a lifetime horizon and one-month cycle length was used to estimate total costs (2024 US$) and quality-adjusted life years (QALYs). The model included three health states: progression-free, progressed disease, and death, with an initial cohort age of 40 years. Disease progression for letrozole and utility values were derived from Thai cohorts, while the efficacy of ribociclib plus letrozole was based on MONALEESA-7 trial data. Dose reductions due to severe adverse events were incorporated. Second- and third-line treatments included paclitaxel and capecitabine, respectively. Costs and outcomes were discounted at 3% annually.
RESULTS: In the base-case analysis, median progression-free survival was 21.6 months, with a 5-year survival rate of 56.9%. The monthly cost of ribociclib was $1,443.9. Ribociclib plus letrozole increased QALYs from 3.39 to 4.01 compared to letrozole alone but incurred higher costs, resulting in an incremental cost-effectiveness ratio (ICER) of $51,385.9/QALY gained. Deterministic sensitivity analysis indicated that the efficacy and the cost of ribociclib plus letrozole had the greatest impact on the ICER, while other key parameters had small effects. Probabilistic sensitivity analysis showed that ribociclib plus letrozole was unlikely to be cost-effective at Thailand’s willingness-to-pay (WTP) threshold of $4,533.2/QALY at its current price.
CONCLUSIONS: At the current drug price, ribociclib plus letrozole is not cost-effective compared to letrozole alone for premenopausal women with HR+/HER2- advanced breast cancer in Thailand.
METHODS: A Markov model with a lifetime horizon and one-month cycle length was used to estimate total costs (2024 US$) and quality-adjusted life years (QALYs). The model included three health states: progression-free, progressed disease, and death, with an initial cohort age of 40 years. Disease progression for letrozole and utility values were derived from Thai cohorts, while the efficacy of ribociclib plus letrozole was based on MONALEESA-7 trial data. Dose reductions due to severe adverse events were incorporated. Second- and third-line treatments included paclitaxel and capecitabine, respectively. Costs and outcomes were discounted at 3% annually.
RESULTS: In the base-case analysis, median progression-free survival was 21.6 months, with a 5-year survival rate of 56.9%. The monthly cost of ribociclib was $1,443.9. Ribociclib plus letrozole increased QALYs from 3.39 to 4.01 compared to letrozole alone but incurred higher costs, resulting in an incremental cost-effectiveness ratio (ICER) of $51,385.9/QALY gained. Deterministic sensitivity analysis indicated that the efficacy and the cost of ribociclib plus letrozole had the greatest impact on the ICER, while other key parameters had small effects. Probabilistic sensitivity analysis showed that ribociclib plus letrozole was unlikely to be cost-effective at Thailand’s willingness-to-pay (WTP) threshold of $4,533.2/QALY at its current price.
CONCLUSIONS: At the current drug price, ribociclib plus letrozole is not cost-effective compared to letrozole alone for premenopausal women with HR+/HER2- advanced breast cancer in Thailand.
Conference/Value in Health Info
2025-09, ISPOR Real-World Evidence Summit 2025, Tokyo, Japan
Value in Health Regional, Volume 49S (September 2025)
Code
RWD320
Topic Subcategory
Reproducibility & Replicability
Disease
SDC: Oncology