Real-World Outcomes of a Non-Medical Switch to Adalimumab-Atto Biosimilar: Safety, Effectiveness, and Treatment Persistence in an Adult Saudi Tertiary Care Population

Abstract

Background Adalimumab-atto, a biosimilar to adalimumab, has been widely adopted for managing autoimmune conditions due to its demonstrated safety, efficacy, and cost-effectiveness in clinical trials. However, real-world data from Saudi Arabian population remains limited. Objective This study aimed to evaluate the persistence, safety, and clinical outcomes of patients transitioned from originator adalimumab (Humira®) to adalimumab-atto biosimilar (Amgevita®) at a tertiary care center. Methods A retrospective self-controlled cohort study was conducted, including all patients transitioned to adalimumab-atto between January 1 and December 31, 2022, for non-medical reasons. The primary endpoint was treatment persistence at 12 months. Secondary endpoints included disease stability, adverse events, and reasons for discontinuation. Results The study included 265 adult patients previously treated with originator adalimumab. The mean age of the cohort was 41 ± 13 years, with 46.8% being female. The most common indications were Crohn’s disease (40.4%), rheumatoid arthritis (16.6%), and plaque psoriasis (12.1%), with a mean disease duration of 11.7 ± 6.7 years. At 12 months, 90.2% of patients persisted with adalimumab-atto, of whom 79.5% remained stable, while 20.5% were classified as unstable Twenty-six patients (9.8%) discontinued therapy, primarily due to insufficient efficacy (13 patients), with one discontinuation attributed to adverse events. Conclusion Adalimumab-atto demonstrated high treatment persistence and favorable safety outcomes in a diverse population of patients with autoimmune diseases. These findings support the feasibility of continued use of the biosimilar in patients with immune-mediated diseases.