Photo Credit: Tonpor Kasa

Bimekizumab has been found to minimize spinal radiographic progression in patients with radiographic axial spondyloarthritis.

New data from the 2 year open-label extension study of BE MOBILE 2 revealed that bimekizumab effectively minimizes spinal radiographic progression in patients with radiographic axial spondyloarthritis (r-axSpA). At 2 years, 85% of participants treated with bimekizumab showed no radiographic progression.

The ongoing open-label extension (NCT04436640) of the phase 3 BE MOBILE 2 study (NCT03928743) assesses the impact of the dual IL-17A and IL-17F inhibitor bimekizumab on spinal radiographic progression over 164 weeks. Prof. Xenofon Baraliakos, MD, from Ruhr-University Bochum, in Germany, presented the interim analysis at week 104¹. “We need at least 2 years to assess radiographic changes,” Prof. Baraliakos explained.

The BE MOBILE 2 study involved 332 participants, 286 of whom entered the OLE, and 267 completed the 104 weeks. Participants received bimekizumab 160 mg subcutaneously every 4 weeks. “Damage at the beginning is the most important factor for further progression; that is why we assessed it at baseline,” Prof. Baraliakos said. Baseline modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) was relatively high with 7.3. Radiographs were repeated at week 104, with progression independently assessed by 2 central readers using the mSASSS (range 0–72).

The results showed only minimal spinal radiographic progression in participants treated with bimekizumab. The mean mSASSS change from baseline was 0.3. No radiographic progression was shown by 85.3% of participants (mSASSS change ≤0.5), and 92.1% showed less than 2 points increase in mSASSS. Moreover, non-progressors in week 104 included 83.1% of participants with pre-existing structural damage.

No significant predictive factors for spinal radiographic progression were identified, including baseline mSASSS, age, sex, BMI, ethnicity, smoking status, baseline ASDAS, baseline hs-CRP, prior TNF inhibitor use, and ASDAS and ASAS40 response at week 104.

Only a minor fraction of participants had new syndesmophytes at 2 years of treatment with bimekizumab, including almost one-fifth who had existing syndesmophytes at baseline. This shows that participants with syndesmophytes at baseline are particularly prone to progress.

Safety data indicated that bimekizumab was well-tolerated, with no unexpected AEs reported.

The high proportion of participants maintaining non-progression status over 2 years in this study supports the use and further investigation of bimekizumab as a viable long-term treatment option for axSpA.