Despite a substantial number of treatment options in rheumatoid arthritis (RA) following tumor necrosis factor inhibitor (TNFi) inadequate response or intolerance (TNF-IR), a lack of clarity on the optimal approach remains. Sarilumab, a human monoclonal anti-interleukin-6 receptor alpha antibody, can be used as monotherapy or in combination with methotrexate or other conventional synthetic disease-modifying anti-rheumatic drugs (DMARDs) in TNF-IR patients.
To conduct a cost-utility analysis from a U.S. health care system perspective for sarilumab subcutaneous 200 mg + methotrexate versus abatacept + methotrexate or a bundle of TNFi + methotrexate for treatment of adult patients with moderately to severely active RA and TNF-IR.
Analysis was conducted via individual patient simulation based on patient profiles from the TARGET trial (NCT01709578); a 6-month decision tree was followed by lifetime semi-Markov model with 6-month cycles. Treatment response at 6 months, informed by network meta-analysis, was based on American College of Rheumatology (ACR) 20/50/70 criteria; patients achieving ≥ ACR20 continued with current therapy, and other patients moved to the next line of biologic DMARD therapy or conventional synthetic DMARD palliative treatment. Direct costs included wholesale acquisition drug costs and administration and routine care costs. Routine care costs and quality-adjusted life-years (QALYs) were estimated by predicting the Health Assessment Questionnaire Disability Index score based on treatment response and were imputed from published equations.
Sarilumab + methotrexate dominated the TNFi bundle + methotrexate, achieving lower costs ($319,324 vs. $356,096) and greater effectiveness (4.27 vs. 4.15 QALYs), and was on the cost-efficiency frontier with abatacept + methotrexate ($360,211 and 4.29 QALYs). Abatacept + methotrexate was not cost-effective versus sarilumab + methotrexate. Scenario analyses indicated the results were robust; sarilumab + methotrexate became dominant against abatacept + methotrexate after reduced model horizon, minimum response based on ACR50 or ACR70, or time to discontinuation per treatment class. Sarilumab + methotrexate was also dominant versus the TNFi bundle; when class-specific time to treatment discontinuation was specified, sarilumab remained cost-effective with an incremental cost-effectiveness ratio of $36,894.
This study was funded by Sanofi and Regeneron Pharmaceuticals. Kiss and Gal are employees of Evidera, which received consulting fees from Sanofi/Regeneron for conducting this study. Muszbek was employed by Evidera at the time of this study. Kuznik and Chen are current employees of and stockholders in Regeneron Pharmaceuticals. Fournier is an employee of and stockholder in Sanofi. Proudfoot is a former employee of and current stockholder in Sanofi and current employee and stockholder in ViiV Healthcare/GlaxoSmithKline. Michaud has received grant funding from Pfizer and the Rheumatology Research Foundation. The sponsors were involved in the study design, collection, analysis, and interpretation of data as well as data checking of information provided in the manuscript. The authors had unrestricted access to study data, were responsible for all content and editorial decisions, and received no honoraria related to the development of this publication.
Sarilumab + methotrexate can be considered an economically dominant (more effective, less costly) option versus a second TNFi + methotrexate; compared with abatacept + methotrexate, it is a less costly but less effective option for patients with moderately to severely active RA who have previously failed TNFi.