Cost-effectiveness of docetaxel compared to paclitaxel in metastatic breast cancer: A UK health economic analysis

Abstract

1081 Background: Docetaxel was shown to be superior to paclitaxel in OS and TTP (median OS: 1.28 vs 1.06 yr, HR=1.41; median TTP: 0.47 vs 0.30 yr, HR= 1.64) for the treatment of patients with metastatic breast cancer progressing after an anthracycline-based regimen (Jones et al. J Clin Oncol. 2005;23:5542). A cost-effectiveness analysis based on this head-to-head comparison was performed considering clinical effectiveness, quality-adjusted life-years, and direct medical costs in the UK. Methods: A probabilistic Markov model was developed to examine results over a 10-yr long time-horizon. Patient level data were available on PFS and OS, treatment cycles and doses, number of cycles affected by adverse events, G-CSF use and post-failure treatment. Generalized gamma regression, fitting patient-level data best were used to model baseline PFS and OS in the paclitaxel arm. HRs adjusting for all covariates were applied to the baseline hazards to generate the docetaxel arm. Resource use and utility values for health states were obtained from published literature and practicing UK oncologists. Unit costs came from 2005 NHS reference costs; drug costs from the British National Formulary 2006 without hospital discount. Costs and benefits were discounted at 3.5%. A Monte-Carlo simulation and extensive 1-way sensitivity analyses were conducted. Results: Docetaxel is more costly (£13,500 vs £10,600), but yields higher health benefits than paclitaxel (2.01 vs 1.48 LYs and 1.18 vs 0.85 QALYs for docetaxel and paclitaxel, respectively) over a 10-yr time horizon. The discounted Incremental Cost-Effectivness Ratio (ICER) of docetaxel vs paclitaxel 3-weekly was estimated to be £5,532/LY gained (95% CI 2,250–12,700) and £8,741/QALY gained (95% CI 3,400–17,300). The ICER was most sensitive to the HR for PFS, OS and the cost of docetaxel and paclitaxel. However, ICERs remained below £20,000/QALY at extreme values of the parameters. Conclusions: Compared with paclitaxel 3-weekly, over a 10-yr time horizon docetaxel provides survival and quality-adjusted survival benefit to metastatic breast cancer patients failing anthracycline regimens at an acceptable cost in a UK setting. Docetaxel is cost-effective compared to paclitaxel. No significant financial relationships to disclose.