In the 24-week phase III MONARCH study, the IL-6 receptor blocker sarilumab was superior to adalimumab in improving the signs and symptoms of rheumatoid arthritis (RA) in patients unable to continue treatment with methotrexate because of intolerance or lack of response. Patients treated with sarilumab monotherapy (200 mg every 2 weeks, administered subcutaneously) had greater changes from baseline in DAS28-ESR at week 24 than those treated with adalimumab monotherapy (40 mg every 2 weeks) (−3.28 versus −2.20; P <0.0001). Additionally, more patients in the sarilumab group achieved clinical remission and low disease activity. Safety profiles of the two treatments were generally comparable; neutropenia and injection site reactions were the most common adverse events in the sarilumab group, and headache and exacerbations of RA in the adalimumab-treated patients. Infection rates were similar across the two groups.