Treatment retention of infliximab and etanercept originators versus their corresponding biosimilars: Nordic collaborative observational study of 2334 biologics naïve patients with spondyloarthritis

Abstract

ObjectiveAlthough clinical trials support equivalence of originator products and biosimilars for etanercept and infliximab, real-world studies among biologics-naïve patients with spondyloarthritis (SpA) are lacking. The objectives were to compare treatment retention in biologics-naïve patients with SpA starting either the originator product or a biosimilar of infliximab and etanercept, and to explore the baseline characteristics of these patients.MethodsPatients with SpA (ankylosing spondylitis/non-radiographical axial SpA/undifferentiated SpA), starting infliximab or etanercept as their first-ever biological disease-modifying antirheumatic drug during January 2014–June 2017 were identified in five Nordic biologics–rheumatology registers. Baseline characteristics were retrieved from each registry; comorbidity data were identified through linkage to national health registers. Country-specific data were pooled, and data on infliximab and etanercept were analysed separately. Comparisons of treatment retention between originators and biosimilars were assessed through survival probability curves, retention rates (2 years for infliximab/1 year for etanercept) and Hazard Ratios (HR).ResultsWe included 1319 patients starting infliximab (24% originator/76% biosimilar), and 1015 patients starting etanercept (49% originator/51% biosimilar). Baseline characteristics were largely similar for the patients treated with the originators compared with the corresponding biosimilars. Survival probability curves were highly similar for the originator and its biosimilar, as were retention rates: infliximab 2-year retention originator, 44% (95% CI 38% to 50%)/biosimilar, 46% (95% CI: 42% to 51%); and etanercept 1-year retention originator, 66% (95% CI 61% to 70%)/biosimilar, 73% (95% CI 68% to 78%). HRs were not statistically significant.ConclusionThis observational study of biologics-naïve patients with SpA from five Nordic countries showed similar baseline characteristics and very similar retention rates in patients treated with originators versus biosimilars, for both infliximab and etanercept, indicating comparable effectiveness in clinical practice.

Efficacy and Safety of Etanercept Biosimilars Compared With the Originator for Treatment of Juvenile Arthritis: A Prospective Observational Study

“…Lindström et al observed 1015 patients who primarily had spondyloarthritis. No increase in disease activity was observed in these patients 6 months after switching from Enbrel to Benepali ( 10 ). The same conclusion was reached by Holroyd et al, who followed‐up 92 adult patients with various rheumatic diseases for at least 6 months after switching from Enbrel to Benepali ( 22 ).…”

“…Both studies showed equivalent efficacy and safety of the biosimilars compared with the originator. In addition, extensive observational studies involving several thousand adult participants have been conducted for both switching from the originator to an etanercept biosimilar during the therapy course and starting therapy with an etanercept biosimilar ( 9 , 10 ).…”

Clinical Trials Supporting the Role of the IL-17/IL-23 Axis in Axial Spondyloarthritis

“…The current recommendations for AxSpa and PsA include this class of drugs on the same line as other mechanisms of action and based on this TNF inhibitors will be mentioned as comparators, as shown in Table 2 (43,44). Besides the anti-TNFa therapies approved in the last 20 years for the treatment of SpA patients (45)(46)(47), with proved efficacy also for the treatment of extraarticular manifestations such as uveitis (RAPID-axSpA ClinicalTrials.gov Identifier: NCT01087762) (48), biosimilars of TNFa inhibitors have become increasingly used, and observational studies of biologics-naïve patients with SpA have shown similar response and safety in patients treated with originators versus biosimilars, indicating comparable effects in clinical practice (49).…”

“…Besides the anti-TNFα therapies approved in the last 20 years for the treatment of SpA patients ( 45 – 47 ), with proved efficacy also for the treatment of extraarticular manifestations such as uveitis (RAPID-axSpA Identifier: NCT01087762) ( 48 ), biosimilars of TNFα inhibitors have become increasingly used, and observational studies of biologics-naïve patients with SpA have shown similar response and safety in patients treated with originators versus biosimilars, indicating comparable effects in clinical practice ( 49 ).…”

A Benchmarking Study Evaluating Axial Spondyloarthritis Burden in Spain and Other European Countries. Results from the Spanish Atlas and the European Map of Axial Spondyloarthritis (EMAS) Studies

“…However, its scope covers only 3 countries of similar geographical and socio‐economic conditions (France, Belgium, and the Netherlands) 8 . Even if great efforts are being made in order to carry out joint studies of different registries that allow for greater generalizability of results, this research is still subject to problems due to the different methodologies used by said registries, leading to sample bias 12 or lack of comparability of the relevant indicators for axSpA patients’ health 13 …”