Antiadalimumab Antibodies in Patients With Inflammatory Ocular Diseases: Incidence and Clinical Outcomes

To determine the incidence, effect on adalimumab drug levels, and clinical consequences of antiadalimumab antibody formation, and to assess potential risk factors.

Retrospective clinical cohort study.

One hundred twenty-eight patients treated with adalimumab who underwent antiadalimumab antibody monitoring.

Beginning October 2023, regularly scheduled antiadalimumab antibody and adalimumab level testing was begun. Using staggered entry analysis, anchored observation to treatment initiation, incidence was calculated. Time-updated models evaluated risk factors for antiadalimumab antibody formation.

Incidence of antiadalimumab antibodies.

Antiadalimumab antibodies developed in 37 of 128 patients for a rate of 0.077 per person-year (PY) (95% confidence interval [CI] 0.055/PY, 0.104/PY). Median serum adalimumab concentrations were significantly lower in antiadalimumab antibody-positive blood samples (2.6 µg/mL; interquartile range 0.8, 7.0) than in antibody-negative samples (10.2 µg/mL; interquartile range 6.9, 15.1), P < .00001. In time-updated analyses, there was a suggestion that concomitant immunosuppression was associated with a reduced risk of antiadalimumab antibodies (odds ratio [OR] 0.64; 95% CI 0.37, 1.10; P = .10) and weekly adalimumab dosing was associated with a reduced risk (OR 0.62; 95% CI 0.42, 0.91; P = .01). Antiadalimumab antibodies were associated with active ocular inflammation (OR 3.68; 95% CI 1.99, 6.82; P < .00001).

Antiadalimumab antibodies occur commonly among patients treated with long-term adalimumab, with a cumulative incidence of nearly 50% by 8 years of therapy. Antibody formation was associated with lower serum adalimumab levels and active ocular inflammation.