Cost-effectiveness of sarilumab added to methotrexate in the treatment of adult patients with moderately to severely active rheumatoid arthritis who have inadequate response or intolerance to tumor necrosis factor inhibitors

BACKGROUND: 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 antirheumatic drugs (DMARDs) in TNF-IR patients. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.