AB0250 REAL-WORLD OUTCOMES IN STABLE ORIGINATOR BIOLOGIC-TREATED ADULT PATIENTS WHO STAYED ON THE THERAPY VERSUS THOSE WHO SWITCHED TO BIOSIMILAR: A RETROSPECTIVE CHART REVIEW STUDY IN EUROPE
Authors: Allan Gibofsky, Martha Skup, Min Yang, Wei Gao, Tahera Doctor
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Biologic therapies have considerably improved clinical management of autoimmune diseases. Over the past few years, several biosimilars have been introduced in Europe for these conditions. Limited information is available evaluating the impact of switching stable patients from originators to their respective biosimilars in clinical practice for non-medical reasons. <h3>Objectives</h3> This real-world study reported and compared patient characteristics, clinical outcomes, and healthcare resource utilization (HRU) associated with stable patients who switched from the originator biologic etanercept to its biosimilar (switchers) vs. those who stayed on the originator (non-switchers) in adults with a rheumatic condition such as ankylosing spondylitis (AS), psoriatic arthritis (PsA), or rheumatoid arthritis (RA). <h3>Methods</h3> Medical record data were retrospectively collected anonymously from rheumatologists in the UK and Germany. Adult patients who were diagnosed with RA, AS, or PsA, treated with originator etanercept for at least 6 months with a stable dosing schedule, and had no emergency department visit or hospitalization for the disease of interest over the 6-month period were eligible for the study. The index date for a non-switcher was the prescription date closest to one year after the initiation of originator etanercept and with a stable dosing for at least 6 months. The index date for a switcher was the biosimilar initiation date. Chart data available for at least 12 months prior to and post the index date were required. Patient characteristics, disease severity, symptoms and signs, and HRU were extracted anonymously. Unadjusted and adjusted comparisons of the outcomes between non-switchers and switchers were conducted among all patients and for each individual disease. <h3>Results</h3> Data were extracted from 242 patient records (non-switchers = 123, 50.8%; switchers = 119, 49.2%; AS=26.4%; PsA=26.0%; RA=47.5%) from 162 rheumatologists. At baseline, non-switchers were significantly younger than switchers (44.5 vs. 48.4 years, p&lt;0.05), had a significantly shorter time on the originator etanercept (11.7 vs. 23.8 months), and more patients had been treated with NSAIDS (55.3% vs. 37.8%). Significantly more non-switchers had moderate, or severe disease (27.6% vs 16.0%, p&lt;0.05; 26.8% vs 5.9%, p&lt;0.01) and non-switchers on average had worse joint or spine pain (4.4 vs 2.4, p &lt;0.01) than switchers. During the follow-up period, significantly more non-switchers' disease status improved (58.5% vs. 25.2%. p&lt;0.01), resulting comparable disease severity (moderate: 10.6% vs 10.9%; severe: 0% vs 0%) and joint or spine pain scale (2.0 vs 1.0) between the two cohorts. After adjusting for potential confounding factors, compared to switchers, more AS and PsA non-switchers improved in disease severity (AS: p&lt;0.05; PsA: p&lt;0.01), and RA non-switchers had a fewer number of swollen joints (0.5 vs 1.5, p&lt;0.01). Non-switchers generally had numerically lower HRU than switchers during the one-year follow-up period (patients with outpatient visits: 76.4% vs 89.1%; average number of outpatient visits: 1.8 vs 2.0). <h3>Conclusion</h3> When compared with stable patients who underwent non-medical switching, stable patients who continued therapy with the originator biologic demonstrated significantly more improvement in disease severity. Other outcomes such as HRU appeared more similar between patients who underwent non-medical switching and patients who continued therapy with the originator biologic. The value of biosimilar non-medical switching requires continued evaluation in real-world clinical practice. <h3>Acknowledgement</h3> Medical writing support provided by Cinzia Metallo of Analysis Group, and funded by AbbVie. <h3>Disclosure of Interests</h3> Allan Gibofsky Shareholder of: AbbVie, Amgen, Johnson&amp;Johnson, Regeneron, Consultant for: AbbVie, Pfizer, Horizon, Celgene, Novartis/Sandoz, Samumed, LLC, Merck, Flexion, Lilly, Speakers bureau: AbbVie, Celgene, Pfizer, Flexion, Lilly, Merck, Martha Skup Shareholder of: Shareholder of AbbVie, Employee of: Employee of AbbVie, Min Yang Consultant for: Employee of Analysis Group, which received consultancy fees from AbbVie, Wei Gao Consultant for: Employee of Analysis Group, which received consultancy fees from AbbVie, Tahera Doctor Consultant for: Employee of Analysis Group, which received consultancy fees from AbbVie