Regeneron Pharmaceuticals Inc. hopes less frequent dosing will position sarilumab favorably compared to the only marketed mAb targeting the IL-6 receptor and that limited patient responsiveness to rheumatoid arthritis therapies overall will leave room in the crowded RA market.

The marketed competition is Actemra tocilizumab, a mAb against IL-6 receptor (CD126) from Roche's Genentech Inc. unit and Chugai Pharmaceutical Co. Ltd.