Discontinuation of biologic and target-specific therapy in patients with rheumatoid arthritis: a retrospective cohort study.

Background: Rheumatoid arthritis is a progressive disease that requires continuous treatment. Despite the excellent results, treatment with biologics and target-specific disease-modifying anti-rheumatic drugs often has to be interrupted due to insufficient therapeutic effectiveness, toxicity, or side effects.

Purpose: The purpose of this study is to identify the reasons and factors influencing treatment discontinuation with biologic and target-specific drugs among the Bulgarian patients with rheumatoid arthritis.

Patients and methods: This is a single-centre, retrospective observational cohort study, that includes 154 patients with seropositive rheumatoid arthritis, who underwent a total of 221 therapeutic courses with biologic and target-specific drugs over a period of 12 years.

Results: Out of the 221 therapeutic courses, 103 (46.6%) were discontinued. Due to an initial lack of efficacy, treatment was interrupted in 38 of cases (36.9%). A secondary lack of efficacy led to the discontinuation of 24 treatment regimens (23.3%). Allergic reactions and "other" reasons necessitated the cessation of therapy in 41 cases (39.8%). The male gender (HR = 2.111; 95%CI 1.261-3.535), age below 59 years (HR = 1.791, 95%CI 1.162-2.760), shorter disease duration (HR = 0.995, 95%CI 0.993-0.998), co-morbidity with diabetes mellitus (HR = 3.463, 95%CI 1.189-10.090), cerebrovascular disease (HR = 2.490, 95%CI 1.215-5.102), and the type of medication were identified as factors influencing the interruption of treatment. Age (p = 0.012), disease duration (р=0.06), and therapy duration (р<0.01) have a significant impact on the reasons for treatment discontinuation.

Conclusions: Awareness of the reasons and factors influencing the discontinuation of treatment with biologic and target-specific drugs is crucial for improving existing therapeutic strategies and developing futures ones.