Bimekizumab Demonstrates Rapid and Sustained Efficacy in Treating NrxSpA, Regardless of Prior TNF Inhibitor Exposure

Bimekizumab (BKZ) demonstrated promising results in improving efficacy outcomes for patients with axial spondyloarthritis (axSpA), even in those who have lost response to TNF inhibitors or are intolerant to them, according to pooled data from two studies.  

TNF inhibitors are the first line of biologic treatment for patients with axSpA, but many may lose response over time or be intolerant to TNF inhibitors. BKZ, a monoclonal antibody that inhibits IL-17F and IL-17A, has shown rapid and sustained improvements in efficacy outcomes in patients with active non-radiographic axial spondyloarthritis (nrxSpA) and radiographic axial spondyloarthritis (rxSpA). 

Researchers designed these studies to assess the efficacy of BKZ in TNFi-naïve or -IR pts with active nrxSpA and rxSpA through week 52 across multiple key endpoints. 

Two separate studies, BE MOBILE 1 and BE MOBILE 2, were conducted to assess the effectiveness of BKZ in patients with axSpA. The criteria for patient inclusion differed between the two studies. In BE MOBILE 1, patients met the Assessment of SpondyloArthritis International Society (ASAS) classification criteria, while in BE MOBILE 2, patients fulfilled modified New York and ASAS criteria.  

The patients were randomly assigned to receive either BKZ or a placebo and those in the BKZ group received regular doses of 160mg every 4 weeks. This analysis presents the pooled efficacy data from both studies, including disease activity, MRI inflammation, physical function, and quality of life. The data is stratified based on the patients' previous experience with TNFi treatment, with subgroups for both TNFi-naïve and TNFi-IR patients, where TNFi-IR refers to patients who had previous intolerance or inadequate response to TNFi treatment for a minimum of 12 weeks at a recommended dosage. 

In this analysis, a total of 586 patients were included, including 505 TNFi-naïve patients and 81 TNFi-IR patients. Of these, 59.8% of TNFi-naïve patients and 58.0% of TNFi-IR patients were randomly assigned to BKZ treatment. At week 16, a higher percentage of TNFi-naïve and TNFi-IR patients who were randomized to BKZ treatment achieved ASAS40 and low disease activity compared to those who received a placebo.  

Furthermore, substantial reductions in disease activity and MRI inflammation were observed in both TNFi-naïve and TNFi-IR patients treated with continuous BKZ therapy, and these improvements were sustained or further improved through 52 weeks. Similar improvements in physical function, nocturnal spinal pain, and ASQoL were also observed in both groups receiving BKZ treatment. 

“Across the full axSpA disease spectrum, BKZ treatment resulted in clinically relevant improvements in key efficacy outcomes vs PBO, including suppression of inflammation and improvements in physical function and QoL, regardless of prior TNFi exposure,” said researchers. “The improvements with BKZ at Wk 16 were sustained to Wk 52.”  

Reference

Magrey M, Van de Sande MGH, Breban M, et al.  Pos1107 Bimekizumab achieved sustained improvements in efficacy outcomes in patients with axial spondyloarthritis, regardless of prior TNF inhibitor treatment: week 52 pooled results from two phase 3 studies. Annals of the Rheumatic Diseases. 2023;82:876-877. doi: 10.1136/annrheumdis-2023-eular.836