Bimekizumab Add-on Therapy in Rheumatoid Arthritis Save

Bimekizumab is a dual inhibitor of IL-17A and IL-17F that has been shown to be effective in psoriasis and psoriatic arthritis. A proof-of-concept study shows that giving bimekizumab to rheumatoid arthritis (RA) patients not adequately controlled by certolizumab pegol (CZP) resulted in a rapid decrease in disease activity achieved after 12 weeks of treatment. These findings are novel as anti-IL-17 monoclonal antibody therapy has previously been shown to be ineffective in RA. 

This phase 2a, double-blind, proof-of-concept study enrolled 159 patients with moderate-to-severe RA who had active disease after 8 weeks of open-label CZP treatment.  There were 79 incomplete responders who continued their CZP but were randomized to either placebo or bimekizumab (240 mg loading dose then 120 mg Q2W). The primary endpoints was the change in DAS28(CRP) at week 20. 

By week 20, there was a greater reduction in DAS28(CRP) in the CZP-IR plus bimekizumab group compared with the CZP-IR plus placebo group (61% vs 48%). The decrease in DAS28(CRP) was -1.41 for the BIM+CZP group vs. -0.82 for the CZP+PBO group. 

There were more overall infections (TEAEs) with CZP plus bimekizumab (50.0%) compared to CZP plus placebo (22.2%). There was only one serious infection in each group by study end. 

These results suggest the possible utility of a dual IL-17 inhibitor, bimekizumab, in RA patients not responding to TNF inhibition.