The following is a summary of “Exploring TNFi drug-levels and anti-drug antibodies during tapering among patients with inflammatory arthritis: secondary analyses from the randomised BIODOPT trial,” published in the July 2024 issue of Rheumatology by Uhrenholt et al.

Researchers conducted a retrospective study assessing tumor necrosis factor inhibitor (TNFi) drug levels and anti-drug antibodies (ADAb) presence in patients with inflammatory arthritis (IA) undergoing disease activity-guided TNFi tapering compared to patients continuing stable TNFi therapy.

They randomized patients with rheumatoid arthritis (RA), psoriatic arthritis, or axial spondyloarthritis who had maintained low disease activity on a stable TNFi dose for at least 12 months in a 2:1 ratio to either disease activity-guided tapering or continued therapy. Blood samples were taken at baseline, 12 months, and 18 months to measure TNFi drug levels and detect ADAb. There were 129 participants, with 88 assigned to the tapering group and 41 to the control group.

The result showed 18 months, the tapering group showed a notable shift in TNFi drug levels, with a 14% decrease in patients with high drug levels (95% CI −27 to −1%) and an 18% increase in those with low drug levels (95% CI 5–31%). Disease activity was comparable between the tapering and control groups, with mean differences of −0.06 (95% CI −0.44 to 0.33) for RA, 0.03 (95% CI −0.36 to 0.42) for psoriatic arthritis, and 0.16 (95% CI −0.17 to 0.49) for axial spondyloarthritis, all within ±0.5 disease activity points. The ADAb was found in 8 patients, all in the tapering group. Neither TNFi drug levels nor ADAb was predictive of successful tapering at 18 months.

Investigators concluded that while tapering TNFi reduced drug levels, disease activity remained stable. ADAb was infrequent, indicating that TNFi drug levels and ADAb may not be effective for guiding tapering decisions and underscoring the need for larger studies.

Source: link.springer.com/article/10.1007/s00296-024-05665-7