Cost-utility analysis of second-line therapy with rituximab compared to tumour necrosis factor inhibitors in rheumatoid arthritis

Objective To compare direct costs and treatment utility associated with the second-line therapy with rituximab and tumour necrosis factor inhibitors (TNFis) (adalimumab, etanercept, and infliximab) in patients with Rheumatoid Arthritis (RA) using data from a prospective registry. Methods Health Assessment Questionnaire Disability Index (HAQ-DI) scores and RA-related healthcare resource utilization data (biologic agents and visits to rheumatologists) were extracted from a registry (Quebec, Canada) for patients with RA (n = 129) who had to discontinue a first-line TNFi and were treated with rituximab, adalimumab, etanercept, or infliximab as the second-line therapy between January 2007 and May 2016. A decision analytic model followed patients for 1 and 6 years. Treatment utility was measured as quality-adjusted life-years (QALYs) gained, which were calculated from HAQ-DI scores observed over the follow-up time. Quebec 2020 unit costs (Canadian Dollars, $) were used to value healthcare resource consumption. A probabilistic sensitivity analysis was performed with 10,000 Monte Carlo simulations to assess uncertainty around point-estimates of cost-utility. Results Over 1-year, rituximab and etanercept resulted in the effectiveness of 0.80 QALYs gained at the cost of $14,291and $18,880, respectively, and were dominant (i.e. associated with lower costs and more QALYs gained) compared to adalimumab (0.79 QALYs, $18,825) and infliximab (0.76 QALYs, $20,158). Over 6-years, rituximab (4.42 QALYs, $82,402) was dominant compared to adalimumab (4.30 QALYs, $101,420), etanercept (4.02 QALYs, $99,191), and infliximab (3.71 QALYs, $100,396). In the probabilistic analysis, rituximab was dominant over adalimumab, etanercept, and infliximab with the probability of 0.51, 0.62, and 0.65, respectively. Conclusion Real-world data revealed differences between alternative biologic agents used as the second-line therapy in terms of both treatment costs for the healthcare system and utility of treatment for patients. Therefore, new guidelines on the order of selecting and switching biologic agents should be explored.