ADALIMUMAB DRUG MONITORING AND TREATMENT ADJUSTMENT TO DRUG ANTIBODIES IN NON-INFECTIOUS UVEITIS

Abstract

To explore the incidence of antibodies against adalimumab (AAA) development in non-infectious uveitis (NIU) and to examine the impact of treatment adjustment in non-responders. Retrospective case series. SETTING: Single-center study. Patients with NIU treated with adalimumab OBSERVATION PROCEDURE: Blood samples for adalimumab and AAA were collected and therapeutic adjustments post-monitoring in non-responders were analyzed including changes in injection intervals, addition of conventional disease-modifying antirheumatic drugs (cDMARD), and treatment alterations to biologic DMARD. Proportion of patients with positive AAA and active uveitis, decrease of AAA at final follow-up by different therapeutic interventions. Of 42 patients who underwent laboratory investigations at 17.9 months after adalimumab initiation, 22 (52.4%) patients who were non-responders demonstrated AAA (1243 ng/mL) with a mean adalimumab trough levels of 3.0 μg/mL, significantly lower than the mean drug levels of patients without AAA (11.8 μg/mL). Fifteen (35.7%) patients were receiving concurrent treatment with a second immunosuppressive agent, but the mean antibody level and the mean adalimumab level were not statistically significantly different from the monotherapy group (P = 0.13 and P = 0.34). Reduction in AAA levels and relapse management was greatest among non-responders who were treated by increasing the adalimumab dose and adding an additional immunosuppressive drug (-3565 ng/mL), followed by patients who were shifted to a different biologic (-1153 ug/mL). The presence of AAA was detected in 88% of non-responder patients and was associated with undetectable adalimumab drug levels. This underscores immunogenicity as a major cause of loss of response in uveitis patients receiving biotherapies. Increasing the dose of adalimumab injections together with the addition of low-dose cDMARDs was the most effective adjustment in immunized non-responders for whom the adalimumab drug concentration was low.