Real-World Cost-Effectiveness of Oxaliplatin in Stage III Colon Cancer: A Synthesis of Clinical Trial and Daily Practice Evidence

Objectives: Previous cost-effectiveness analyses of oxaliplatin have been based on randomised trials whereas current Dutch policy requires evidence from daily practice. The objective of this study was to examine the real-world cost-effectiveness of oxaliplatin plus fluoropyrimidines (FL) versus FL-only as adjuvant treatment of stage III colon cancer.
Methods: A Markov model was developed to estimate lifetime cost and quality-adjusted life-years from a hospital perspective. The effectiveness of the oxaliplatin arm was modelled by combining published efficacy data from the pivotal clinical registration trial (MOSAIC trial) with realworld (RW) data from a Dutch population-based observational study. RW patients were categorised into ‘‘eligible’’ or ‘‘ineligible’’, depending on whether the patients fulfilled the MOSAIC trial eligibility criteria. Ineligible RW patients (18 %) had a poorer prognosis than eligible RW patients (82 %) and MOSAIC trial patients. The effectiveness of the comparator was modelled using MOSAIC trial results. All cost inputs were based on RW patients and reported in Euro 2012.
Cost-effectiveness analyses were performed for four different scenarios:
(1) cost-effectiveness analyses based on MOSAIC trial patients;
(2) costeffectiveness analyses using MOSAIC and eligible RW patients;
(3) cost-effectiveness analyses using MOSAIC and both eligible and ineligible RW patients, assuming oxaliplatin had an equal effect in ineligible and eligible patients;
(4) cost-effectiveness analyses using MOSAIC and both eligible and ineligible RW patients, assuming oxaliplatin had no effect amongst ineligibles.
For each scenario, univariate and probabilistic sensitivity analyses were undertaken.
Results: MOSAIC trial patients and eligible RW patients treated with oxaliplatin had comparable 2-year disease-free survivals (79.5 vs. 78.4 %). Oxaliplatin showed an incremental QALY gain of 1.02, 1.13, 1.17 and 0.93 and incremental cost of €9,961, €11,055, €9,814 and €11,854 in scenarios 1–4, respectively. The corresponding incremental cost-effectiveness ratios (ICERs) were €9,766, €9,783, €8,388 and €12,746 in scenarios 1–4, respectively. In all scenarios, univariate and probabilistic sensitivity analyses indicated that the ICERs are acceptable and robust under a wide range of model assumptions.
Conclusions The ICERs of the different scenarios that resulted from combining MOSAIC trial data with data from Dutch daily practice all suggest that FL ? oxaliplatin is cost-effective versus FL alone in the adjuvant treatment of colon cancer. This article illustrates how one could design and implement a real-world cost-effectiveness study to yield internally valid results that could also be generalisable.