PT - JOURNAL ARTICLE AU - Thomas Dörner AU - Vibeke Strand AU - Gilberto Castañeda-Hernández AU - Gianfranco Ferraccioli AU - John D Isaacs AU - Tore K Kvien AU - Emilio Martin-Mola AU - Thomas Mittendorf AU - Josef S Smolen AU - Gerd R Burmester TI - The role of biosimilars in the treatment of rheumatic diseases AID - 10.1136/annrheumdis-2012-202715 DP - 2013 Mar 01 TA - Annals of the Rheumatic Diseases PG - 322--328 VI - 72 IP - 3 4099 - http://ard.bmj.com/content/72/3/322.short 4100 - http://ard.bmj.com/content/72/3/322.full SO - Ann Rheum Dis2013 Mar 01; 72 AB - The first biological therapeutics in rheumatology are approaching patent expiration, encouraging development of ‘follow-on’ versions, known as ‘biosimilars’. Biological agents range from simple replacement hormones to complex monoclonal antibodies and soluble receptors: large, intricate proteins with unique tertiary and quaternary structures that are inherently difficult to replicate. Post-translational modifications, such as glycosylation, may occur from changes in cell lines and/or manufacturing processes, resulting in products that are highly similar, but not identical, to approved ‘reference’ agents, hence, the term ‘biosimilar’, rather than ‘bioidentical’. Even minor modifications in manufacturing processes, which iteratively occur with reference products due to improvements in efficiency, scale up to meet commercial demands or changes in manufacturing sites, may alter biological function and/or immunogenicity, potentially changing their safety and efficacy profile. As biosimilars are now in randomised controlled trials for treatment of rheumatic diseases, rheumatologists face decisions regarding equipoise and will need to consider their clinical use versus reference products. A clear understanding of the inherent differences between reference antibodies and biosimilars, their clinical implications and the processes governing regulation, approval and clinical use of biosimilars, is paramount. A panel of international experts in the field of rheumatology recently convened to evaluate and discuss these issues.