Drug Retention Time of Immunosuppressive Therapy in Behcet's Uveitis

Behcet's Disease is a chronic multisystem vasculitis associated with a blinding uveitis. Few comparative studies exist between conventional disease-modifying antirheumatic drugs (DMARDs) and biologic DMARDs in Behcet's uveitis (BU). We therefore used drug retention time (DRT), an accepted surrogate measure of pharmacological efficacy and tolerability, to compare these treatments in patients with BU.

Retrospective chart review of patients who met the revised International Criteria for Behcet's Disease (ICBD) treated at the Royal Victorian Eye and Ear Hospital, Australia, between 1985-2021. DRT was analysed with Kaplan-Meier plots and defined as total time on drug in the first medication-period for each DMARD in each patient.

Forty-eight patients (37 males) with median age of 28.6 years were followed-up for a median of 8.0 years. At initial presentation, half had bilateral disease and median logMAR visual acuity was 0.176 (Snellen 6/9) in 62 uveitic eyes (16 anterior uveitis, 11 intermediate, 2 posterior, and 33 panuveitis). Thirty-three patients met ICBD initially. Prescribed corticosteroid-sparing agents were Cyclosporin (N = 24), Mycophenolate (N = 22), Azathioprine (N = 22), Methotrexate (N = 16), and Adalimumab (N = 15). Median DRT was 14.0, 27.4, 8.3, 24.0, and 52.0 months, respectively. DMARDs were discontinued 116 times and adverse effects (N = 37) were the main reason for cessation. Over time, patients were switched from Cyclosporin to Adalimumab earlier in the disease course due to poorer tolerance of adverse events.

Adalimumab's drug retention time was found to be similar to and possibly better than cDMARDs in patients with BU, who often suffer from vision-threatening disease at first presentation.