Ann Rheum Dis 2016. DOI 10.1136/annrheumdis-2016-210310In this Phase 3 superiority study (MONARCH) of patients with active RA who should not continue treatment with MTX because of intolerance or inadequate response, sarilumab monotherapy demonstrated superior efficacy to adalimumab (ADA) monotherapy. Patients receiving sarilumab versus ADA also reported greater improvement in health status, including a trend towards greater improvement in fatigue.In this randomised, multicentre study, patients received sarilumab 200 mg Q2W plus placebo (n=184) or ADA 40 mg Q2W plus placebo (n=185) for 24 weeks. The primary endpoint was change from baseline in DAS28-ESR at Week 24. Sarilumab was superior to ADA in mean change from baseline to Week 24 in DAS28-ESR (–3.28 vs –2.20; P<0.001). Sarilumab-treated patients also achieved significantly higher ACR20/50/70 responses (all P<0.01). Additionally, sarilumab-treated patients had significantly greater improvement in HAQ-DI (P=0.0037). More patients receiving sarilumab compared with ADA achieved CDAI remission and LDA (7.1% vs 2.7%, and 41.8% vs 24.9%, respectively).The safety profiles of sarilumab and ADA monotherapy were generally comparable (and consistent with class effects), as were incidences of infections and serious infections, despite more neutropenia in the sarilumab group (25 [13.6%] vs 1 [0.5%]).There is a need for data comparing biological monotherapy performance. Data reported here may help define strategies for treatment choice and optimal sequencing in clinical practice for patients who are intolerant or have inadequate response to MTX.