Certolizumab pegol compared to natalizumab in patients with moderate to severe Crohn's disease: results of a decision analysis.

INTRODUCTION: A significant proportion of patients with Crohn's disease (CD) lose response to antibodies directed against tumor necrosis factor α (TNF). Prior TNF-antagonist failure is associated with lower rates of response to subsequent TNF-antagonist therapy. In patients failing two anti-TNF agents, a choice exists between using a third-anti-TNF therapy or natalizumab (NAT), an α-4 integrin inhibitor. A cost-effectiveness analysis comparing these competing strategies has not been performed. METHODS: A decision analytic model was constructed to compare the performance of certolizumab pegol (CZP) versus NAT in patients with moderate to severe CD. Previously published estimates of efficacy of third-line anti-TNF therapy and NAT were used to inform the model. Costs were expressed in 2010 US dollars. A 1-year time frame was used for the analysis. RESULTS: In the base case estimate, use of NAT was only marginally more effective [0.71 vs. 0.70 quality adjusted life-years (QALYs)] than CZP but was expensive with an incremental cost-effectiveness ratio (ICER) of $381,678 per QALY gained. For CZP 2 months response rate of at least 24%, NAT had an ICER above the willingness-to-pay (WTP) threshold. The model was sensitive to the costs of both therapies; for all CZP costs below $2,300 per dose, NAT had higher ICER than the WTP threshold. Substituting adalimumab for CZP resulted in similar ICER estimates and thresholds for NAT use. CONCLUSIONS: In patients with moderate to severe CD failing two TNF-antagonists, using a third TNF-antagonist therapy appears to be a cost-effective strategy without significantly compromising treatment efficacy.