OP0313 COST-EFFECTIVENESS OF A JAK1/JAK2-INHIBITOR VS. A BIOLOGIC DISEASE-MODIFYING ANTIRHEUMATIC DRUG IN A TREAT-TO-TARGET STRATEGY FOR RHEUMATOID ARTHRITIS
Authors: Celine van de Laar, Martijn Oude Voshaar, Walid Fakhouri, Liliana Zaremba-Pechmann, Francesco de Leonardis, Inmaculada De La Torre, Mart van de Laar
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Treating Rheumatoid Arthritis (RA) to an a priori defined disease activity target (T2T) is recommended in EULAR guidelines. This involves a step-up approach in which it is first attempted to achieve the target with a combination of conventional synthetic (cs) DMARDs. Baricitinib is a JAK1/JAK2-inhibitor approved for treatment of patients suffering from RA. EULAR and ACR guidelines currently position JAK1/JAK2-inhibitors and bDMARDs at the same level in the therapeutic treatment sequence for csDMARD Inadequate Responders (IR). Cost-effectiveness assessment of different T2T strategies, especially ones including new treatments, and integrating health economic considerations is of importance to the decision-making process as it incorporates the societal perspective in the longer run. <h3>Objectives:</h3> To compare the cost-effectiveness of the previously evaluated DREAM T2T strategy csDMARD combination therapy (csDMARDs)→ first bDMARD (adalimumab)→ next bDMARD (TNFi/non-TNFi) with the comparable strategy in which baricitinib is placed instead of adalimumab in csDMARDs IR using a Markov model. All analyses were performed from the societal perspective. Costs and effects over five years were compared between the two strategies to provide insight into the differences in economic considerations between treating patients with strategies including either JAK1/JAK2-inhibitor (baricitinib) or 1<sup>st</sup> bDMARD (adalimumab). <h3>Methods:</h3> A Monte Carlo microsimulation model was developed to conduct cost-utility analysis from the societal perspective over 5 years. Health states were based on the DAS28-ESR categories. Effectiveness of baricitinib was retrieved from clinical trials (1) and corrected for differences between RCT and real-world setting. Effectiveness of all other treatments, health state utilities, medical costs, and productivity loss were retrieved from DREAM cohorts (2) and the Dutch Institute for Health. Annual discount rates of 1.5% for utility and 4% for costs were used, as advised in Dutch guidelines. All analyses were run using probabilistic sensitivity analysis (PSA) to incorporate uncertainty around all parameters and assess result robustness. <h3>Results:</h3> PSA results showed the baricitinib strategy yielded lower costs and higher utility over a 5-year period and is cost-effective and dominant over the DREAM T2T strategy. Scenario analyses showed the baricitinib strategy to be cost-effective in both the moderate and severe at baseline RA populations analysed together and separately. CI= 95% Confidence Interval, QALY = Quality-Adjusted Life Year, ΔC = Cost difference, ΔE = Effect Difference, ICER = Incremental Cost-Effectiveness Ratio <h3>Conclusion:</h3> Results suggest the use of a JAK1/JAK2-inhibitor (baricitinib) instead of a 1<sup>st</sup> bDMARD (adalimumab) in a T2T strategy is cost-effective in treating RA patients. <h3>References:</h3> [1] Taylor, P. C., Keystone, E. C., van der Heijde, D., Weinblatt, M. E., del Carmen Morales, L., ... &amp; Arora, V. (2017). Baricitinib versus placebo or adalimumab in rheumatoid arthritis. New England Journal of Medicine, 376(7), 652-662. [2] M., Versteeg, G. A., Vonkeman, H. E., Ten Klooster, P. M., Kuper, H. H., ... &amp; van de Laar, M. A. (2016). Initial combination therapy versus step-up therapy in treatment to the target of remission in daily cl. Steunebrink, L. inical practice in early rheumatoid arthritis patients: results from the DREAM registry. Arthritis Research &amp; Therapy, 18(1), 60. <h3>Disclosure of Interests:</h3> Celine van de Laar: None declared, Martijn Oude Voshaar: None declared, WALID FAKHOURI Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Liliana Zaremba-Pechmann Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Francesco de Leonardis Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Inmaculada De La Torre Shareholder of: Eli Lilly and Company, Employee of: Eli Lilly and Company, Mart van de Laar Grant/research support from: Eli Lilly, Pfizer, Merck, AbbVie and Janssen Cilag, Consultant for: Sanofi Genzym, Eli Lilly, Pfizer, Merck, Abbvie and Janssen Cilag, Speakers bureau: Eli Lilly, Pfizer and Janssen Cilag