Shawn Yee, Mercer University College of Pharmacy
Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints. Disease-modifying antirheumatic drug (DMARD) therapy, such as methotrexate (MTX) is commonly used for the treatment of RA. However, for patients unresponsive or refractory to this therapy, a newer treatment with monoclonal antibodies (mAb) is being further studied. 
One of the proposed underlying mechanisms of RA includes the activity of interleukin-6 (IL-6) in the joints, where higher levels of IL-6 is associated with joint damage and inflammation. [1,2] Therefore, inhibiting the activity of IL-6 with drug therapy is thought to improve RA symptoms and overall disease progression.  Previous studies analyzing the effect IL-6 receptor antagonism with monoclonal antibodies such as tocilizumab and sarilumab found success with improving RA outcomes, and showed reduction in RA symptoms, improved physical function and reduced the rate of RA progression. [3,4,5,6]
In a previous phase II trial, sirukumab (selective IL-6 cytokine human mAb), showed efficacy in patients refractory to MTX therapy.  The phase III trial is summarized below.