Characteristics of patients who developed transient anti-adalimumab antibodies.

Background: Adalimumab is a monoclonal antibody approved for the treatment of autoimmune diseases and non-infectious uveitis (NIU). It targets tumor necrosis factor alpha, a key mediator in inflammation. However, the development of anti-adalimumab antibodies (AAA) can reduce therapeutic efficacy and prompt treatment modifications. This study aimed to describe the clinical characteristics of patients with transient AAA and compare them to patients with persistent AAA, testing whether serum antibody and drug levels differ between groups.

Main body: We conducted a retrospective cohort study using the Stanford Research Repository (STARR) to identify patients treated with adalimumab for autoimmune conditions between June 2006 and May 2024 who developed AAA. Patients whose AAA became undetectable on follow-up testing were compared to an age-, sex-, and disease-matched cohort with persistent AAA. Demographics, diagnoses, treatment details, serum adalimumab and AAA levels, and concomitant immunomodulatory therapy (IMT) were analyzed. Among 190 AAA-positive patients, 18 (9.47%) demonstrated antibody resolution over a median follow-up of 6.5 months. These patients had lower median AAA levels (39.55 ng/mL vs. 92.35 ng/mL, p=0.020) and higher adalimumab levels (6.25 μg/mL vs. 1.55 μg/mL, p=0.018) than controls. AAA resolution was negatively correlated with AAA levels (p=0.018) and positively correlated with adalimumab levels (p=0.016).

Conclusions: Therapeutic monitoring of AAA and drug levels may help guide personalized therapeutic strategies and support continued treatment in selected patients.