PCN122 COST-EFFECTIVENESS ANALYSIS OF TRASUTUZUMAB EMTANSINE VERSUS TRASTUZUMAB FOR WOMEN WITH HER2+ ADJUVANT BREAST CANCER IN FRANCE

Abstract

To evaluate the cost-effectiveness of trastuzumab emtansine in women with HER2+ adjuvant breast cancer and a finding of residual invasive disease in the breast or axillary lymph nodes after preoperative systemic treatment in France. A six health states Markov model (invasive disease-free survival, non-metastatic recurrence, remission from a non-metastatic recurrence, first-line treatment of metastatic disease, subsequent treatment lines of metastatic disease and death) adapted to the French setting was used to estimate costs and benefits of trastuzumab emtansine versus trastuzumab on a lifetime horizon. Transition probabilities were derived from KATHERINE in the non-metastatic health-states, a randomized phase III clinical trial comparing trastuzumab emtansine versus trastuzumab, and survival and risk of progression in metastatic health-states were derived from EMILIA in case of recurrence within 18-months and from CLEOPATRA and M77001 for later recurrence. Health state utilities were estimated from the KATHERINE trial in the non-metastatic health states using EQ-5D-3L adjusted to the French population and from literature for the metastatic health states. Costs (2019) were calculated from a wide payer perspective (collective). Grade 3-4 adverse events (AE) were considered with impact on cost and loss of quality of life. Costs and outcomes were discounted at 4%. Sensitivity and scenario analyses were performed. Compared to trastuzumab, trastuzumab emtansine was associated with a gain of 2.05 (15.21 versus 13.17) quality-adjusted life years (QALYs) and a gain of 1.93 (16.70 versus 14.77) life years (LYs) and an incremental cost of €15,453 mostly driven by treatment costs. The incremental cost-utility ratio (ICUR) was €7,553/QALY and the incremental cost-effectiveness ratio was €8,014/LY. The present evaluation suggest that, compared to a trastuzumab, trastuzumab emtansine seems to be a promising cost-effectiveness option for treating HER2+ adjuvant breast cancer in France. Results should be confirmed by using French adjusted utility values.