Cost-Effectiveness of T-DM1 vs. Trastuzumab for Adjuvant Treatment in HER2 Early Breast Cancer (eBC) With Residual Disease in Colombia
Author(s)
Melissa Diaz, MSc, MD1, Diego Ballén, MD2, MILTON LOMBANA, MD3, Daniel Samaca, BS Psych, MSc1, Claudia Hernández-Castillo, RN, MSc1, Juliana Saavedra, MD, MSc4.
1Evidence Generation, Roche Colombia, Bogotá, Colombia, 2Instituto Nacional de Cancerología, Bogota, Colombia, 3Clínica de Occidente, BOGOTA, Colombia, 4Medical Affairs, Roche Colombia, Bogotá, Colombia.
1Evidence Generation, Roche Colombia, Bogotá, Colombia, 2Instituto Nacional de Cancerología, Bogota, Colombia, 3Clínica de Occidente, BOGOTA, Colombia, 4Medical Affairs, Roche Colombia, Bogotá, Colombia.
OBJECTIVES: To conduct a cost-effectiveness model of trastuzumab emtansine (T-DM1) compared to trastuzumab as adjuvant therapy for residual invasive HER2+ eBC post-neoadjuvant treatment, from the Colombian Health System perspective.
METHODS: A Markov model with 1-month cycles and a 48-year (lifetime) horizon was developed, comprising health states for patients in invasive disease without recurrence, non-metastatic recurrence, remission after non-metastatic recurrence, metastatic disease (first line[1LmBC] and subsequent lines[2LmBC]), and death. Clinical inputs for T-DM1 were sourced from the KATHERINE trial (median 8.4 years follow-up). Direct medical costs for 2024 were included, using national claim databases and tariff manuals. Outcomes were expressed as quality-adjusted life years (QALYs). A 5% annual discount rate was applied for cost and effects. Sensitivity and scenario analyses were conducted. Model assumptions followed current treatment guidelines and were validated by local clinical experts.
RESULTS: In the base case, under a willingness-to-pay threshold of 86% of 1 Gross Domestic Product (GDP) per capita 2024 (USD6,831), T-DM1 was cost-effective and dominant over trastuzumab (herceptin and biosimilar), yielding an incremental cost-effectiveness ratio (ICER) of USD-3,142. Cost savings were driven by reduced recurrences, particularly in costly settings: 1LmBC (USD-30,510), and 2LmBC (USD-6,317) per modeled patient. TDM-1 reduction in recurrence at 3 years was 50.7%, leading to early cost offsets. TDM-1 dominance was maintained when the average weight(67kg) was lower to 60kg, showing consistency with a sensitive model parameter. Probabilistic sensitivity analysis found T-DM1 was dominant in 81.2% of the Montecarlo simulations, showing robustness with the main results: ICER (USD-3,633).
CONCLUSIONS: T-DM1 is a cost-effective and dominant strategy for the adjuvant treatment of residual invasive HER2+ eBC in Colombia, driven by cost savings from reduced high-cost recurrences, particularly in the metastatic setting. These findings were robust across sensitivity analyses and aligned with current clinical practice guidelines, supporting the long-term value and efficiency of T-DM1 in national cancer care.
METHODS: A Markov model with 1-month cycles and a 48-year (lifetime) horizon was developed, comprising health states for patients in invasive disease without recurrence, non-metastatic recurrence, remission after non-metastatic recurrence, metastatic disease (first line[1LmBC] and subsequent lines[2LmBC]), and death. Clinical inputs for T-DM1 were sourced from the KATHERINE trial (median 8.4 years follow-up). Direct medical costs for 2024 were included, using national claim databases and tariff manuals. Outcomes were expressed as quality-adjusted life years (QALYs). A 5% annual discount rate was applied for cost and effects. Sensitivity and scenario analyses were conducted. Model assumptions followed current treatment guidelines and were validated by local clinical experts.
RESULTS: In the base case, under a willingness-to-pay threshold of 86% of 1 Gross Domestic Product (GDP) per capita 2024 (USD6,831), T-DM1 was cost-effective and dominant over trastuzumab (herceptin and biosimilar), yielding an incremental cost-effectiveness ratio (ICER) of USD-3,142. Cost savings were driven by reduced recurrences, particularly in costly settings: 1LmBC (USD-30,510), and 2LmBC (USD-6,317) per modeled patient. TDM-1 reduction in recurrence at 3 years was 50.7%, leading to early cost offsets. TDM-1 dominance was maintained when the average weight(67kg) was lower to 60kg, showing consistency with a sensitive model parameter. Probabilistic sensitivity analysis found T-DM1 was dominant in 81.2% of the Montecarlo simulations, showing robustness with the main results: ICER (USD-3,633).
CONCLUSIONS: T-DM1 is a cost-effective and dominant strategy for the adjuvant treatment of residual invasive HER2+ eBC in Colombia, driven by cost savings from reduced high-cost recurrences, particularly in the metastatic setting. These findings were robust across sensitivity analyses and aligned with current clinical practice guidelines, supporting the long-term value and efficiency of T-DM1 in national cancer care.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
EE279
Topic
Economic Evaluation
Disease
Oncology