Real-World Experience with an Adalimumab Biosimilar (ABP 501) in Patients with Rheumatoid Arthritis, Ankylosing Spondylitis, Psoriatic Arthritis and Psoriasis in Europe: Results from the Adelphi Disease Specific Programme.

Introduction: Biosimilars have provided additional treatment options for patients with immune-mediated inflammatory diseases. This study evaluated the real-world use of adalimumab biosimilar ABP 501 in European patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), or psoriasis (PsO).

Methods: Data were drawn from the RA, spondyloarthritis, and PsO Adelphi Disease Specific Programmes (DSP)™, cross-sectional surveys conducted in France, Germany, Italy, Spain, and the UK between January 2020 and February 2022. Physicians completed patient record forms which collected data on demographics, treatment history, and clinical outcomes. Patients voluntarily completed questionnaires self-reporting health-related quality of life. Outcome measures were assessed for patients who initiated ABP 501 as the first advanced therapy (AT, "ABP 501 initiators") and patients who switched to ABP 501 from the first-line AT with reference product (RP) ("RP-ABP 501 switchers") in each indication.

Results: Across disease cohorts, 868 initiators and 428 switchers were analyzed. At time of consultation, physicians reported that 77.1%, 63.2%, 67.8%, and 83.0% of initiators with RA, AS, PsA, and PsO, respectively, presented with mild disease after receiving ABP 501 for a median of 10.4-12.3 months. Among switchers, the most common reasons for switching were related to formulary or financial reasons and insurance restrictions. Most switching patients were assessed by physicians to have mild disease (75.0-87.5% across indications) at time of consultation having received ABP 501 for a median of 11.2-15.3 months. Patients' self-assessment, including EQ-5D and work productivity scores, indicated an overall good state of health while using ABP 501, regardless of indication and prior RP exposure. Overall, more than 89% of physicians and more than 86% patients reported being satisfied with the disease control provided by ABP 501.

Conclusion: Across indications, both physicians and patients reported positive clinical outcomes and high levels of satisfaction with ABP 501 treatment, regardless of prior use of RP.