Sa1108 Cost-Effectiveness of Golimumab Versus Infliximab and Adalimumab for the Treatment of Moderate to Severe Ulcerative Colitis

Abstract

Introduction: The efficacy and safety of golimumab was elucidated in the recently published PURSUIT trial. Two other biologics, infliximab and adalimumab, are also available for the treatment of UC. Based on an indirect treatment comparison, golimumab is comparable in efficacy and safety to infliximab, but generally less costly, and superior to adalimumab in efficacy in terms of sustaining clinical outcomes, but generally of similar cost. For this reason, a cost-effectiveness (CE) analysis comparing the three anti-TNF-α agents was warranted. Methods: A Markov Model was created to simulate patients over a 10 years. The first administered intervention was any of the three biologics. Key health states included clinical remission, clinical response, and relapse. Upon relapsing the administered biologic, patients were assumed to transition into ‘relapse management', in which continual IV steroids could keep patients in response until they became refractory. Patients would then undergo colectomy and enter ‘post-colectomy remission'. After colectomy patients could either be in remission or experience temporary colectomy complications. Utilities were assigned separately for states before and after colectomy. Canadian cost estimates were used for biologics, background treatment, and all in/out-patient costs for colectomy and safety outcomes. Uncertainty around transition probability and cost estimates were incorporated. Sensitivity analyses included a societal perspective, varying discount rates and time horizons, and ‘real world' transition probabilities. Analysis: The cost-effectiveness of golimumab was compared with conventional therapy and with infliximab and adalimumab. CE measures included total cost and utility over 10 years, mean incremental cost and utility per year, incremental CE ratios (ICERs), CE acceptability curves (CEACs) for golimumab and the CE frontier for all biologics. Results: In all analyses golimumab yielded the lowest ICER. In the base case analysis, golimumab, infliximab, and adalimumab were associated with an ICERs of approximately $40,000/QALY, $80,000/QALY, and $100,000/QALY, respectively. The CEAC for golimumab showed that a willingness-to-pay threshold (WTPs) of $100,000/QALY was associated with a ~90% probability of being cost-effective. The cost-effectiveness frontier demonstrated that WTP thresholds greater than $25,000 showed that golimumab had the greatest probability of being cost-effective. Golimumab and infliximab displayed extended dominance compared to adalimumab. Sensitivity analysis taking a societal perspective or using ‘real world' transition probabilities reduced the ICERs by 20-40% for all biologics. Conclusion: Overall golimumab provides a cost-effective treatment option for patients who have had an inadequate response to conventional therapy for moderately to severely active ulcerative colitis.