Factors Associated with the Development of Anti-drug Antibodies to TNFi and the Consequences for Axial Spondyloarthritis: A Two-year Follow-up Study.

OBJECTIVE

To evaluate the development of anti-drug antibodies (ADAb) against tumor necrosis factor inhibitors (TNFi) therapy during a 2-year period and search the factors linked to patients with axial spondyloarthritis (axSpA).

METHODS

Biologic-naive patients with axSpA were included in this observational study. Serum drug levels and ADAb were measured at weeks 12, 24, 52, and 104 of treatment by enzyme-linked immunosorbent assay (ELISA). The development of ADAb and factors related to ADAb over time were investigated using generalized estimating equations (GEE).

RESULTS

A total of 180 patients with axSpA (116 male, mean (±SD) 45.6 (±11.9) years) who started TNFi treatment (etanercept (32.2%), adalimumab (27.2%), golimumab (20.6%), infliximab (20%)) were included. In the etanercept treatment group, only 1 patient had ADAb at 12 weeks and 24 weeks. Anti-drug antibodies against TNFi drugs were present in the adalimumab group in 32.7% of patients and in the infliximab group in 21.2% of patients at 12 weeks, and the proportion of ADAb-positive patients were found to be stable throughout the follow-up for adalimumab- and infliximab-treated patients. In the golimumab group, one patient had ADAb against golimumab at 12 weeks and the proportion of ADAb-positive patients increased throughout follow-up. In longitudinal analysis, baseline age, TNFi type, longitudinal Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and ASDAS-CRP scores, serum C-eeactive protein (CRP) levels, presence of adverse events and treatment discontinuation were associated with the presence of ADAb.

CONCLUSION

The development of ADAb against TNFi therapy is associated with younger age, high disease activity, the development of adverse events and more common treatment discontinuation in patients with axSpA during 2-year follow-up.