Efficacy and Safety of Anti–Interleukin‐20 Monoclonal Antibody in Patients With Rheumatoid Arthritis: A Randomized Phase IIa Trial

Objective Interleukin‐20 (IL‐20) is implicated in the pathogenesis of rheumatoid arthritis (RA). The efficacy, safety, and tolerability of NNC0109‐0012, a selective anti–IL‐20 recombinant human monoclonal antibody (mAb), were assessed in patients with active RA who had an inadequate response to methotrexate therapy. Methods Sixty‐seven patients with RA were enrolled and randomized (2:1) to receive NNC0109‐0012 (3 mg/kg per week, subcutaneously) or placebo in a phase IIa, double‐blind, 12‐week trial with a 13‐week followup. The primary end point was change in the Disease Activity Score in 28 joints based on C‐reactive protein level (DAS28‐CRP) from baseline to week 12. Results In patients treated with NNC0109‐0012, the primary end point, improvement in the DAS28‐CRP at week 12, was achieved (estimated difference −0.88; P = 0.02), with significant improvement starting at week 1. A greater response was observed in seropositive patients (estimated difference −1.66; P