The model-based cost-effectiveness analysis of 1-year adjuvant trastuzumab treatment: based on 2-year follow-up HERA trial data.
BACKGROUND
Several randomized controlled trials have confirmed the usefulness of trastuzumab as an adjuvant therapy for HER2-overexpressed breast cancer patients; however, the costs for 1-year treatment are high. Therefore, we performed an economic analysis regarding the efficient distribution of medical resources.


METHODS
To analyze the cost-effectiveness for a 1-year adjuvant trastuzumab treatment group compared with the observation group, we constructed a Markov model adopting a 3% per year discount rate for costs and outcomes. The time horizon was 50 years. The perspective was that of health-care payers, as only direct medical costs were calculated. The outcome was measured as life-year gained (LYG) from 2-year follow-up HERA trial data.


RESULTS
The ICER of the standard setting (5 years efficacy and 50-60 kg patient weight) was JPY 2,600,000 (<euro>17,000) per LYG. The calculation results of other weight class ICER were JPY 2,200,000 (<euro>15,000) and JPY 3,300,000 (<euro>22,000) per LYG for the patients, respectively, who weighed less than 50 kg, and 60-75 kg. In the sensitivity analysis, the period of trastuzumab efficacy was the most influential parameter for the result of cost-effectiveness. However, even if the trastuzumab efficacy were to continue for only 2 years, at least, which is a conservative setting judging from the joint analysis (NSABP B-31 and NCCTG N9831 trials), the ICER remains acceptable for any weight class.


CONCLUSIONS
These results suggest that the 1-year adjuvant trastuzumab treatment is cost-effective. Both clinical and economic benefits were superior for the 1-year adjuvant trastuzumab treatment group compared with the observation group.
Shiroiwa
Takeru
T
Department of Drug Policy and Management, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. t.shiroiwa@gmail.com
Fukuda
Takashi
T
Shimozuma
Kojiro
K
Ohashi
Yasuo
Y
Tsutani
Kiichiro
K
D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D003362:Cost-Benefit Analysis; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D000068878:Trastuzumab
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068878:Trastuzumab