Biosimilars: a regulatory perspective from America

Over the past decade, the availability of targeted biological therapies has revolutionized the treatment of rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis and holds promise to expand treatment options for patients with systemic lupus erythematosus or other systemic autoimmune diseases. However, the significant cost of these medications creates a major barrier that limits universal access to these effective therapeutic agents. Whereas generic equivalents are commercially available for many small-molecule medications, such lower-cost alternatives to targeted biological therapies are not yet available in the US or the European Union.Biopharmaceuticals are medications, predominantly proteins, that are manufactured using live organisms. These include blood and plasma products, non-recombinant proteins purified from their natural sources, recombinant proteins and monoclonal antibodies produced in cell culture, vaccines, and cultured cellular and tissue products [1]. 'Follow-on' protein products are those 'manufactured using biotechnology or derived from natural sources that are intended to be sufficiently similar to a' biopharmaceutical 'product or products' already approved by a regulatory agency [2]. These are called biosimilars and also have been referred to as biogenerics or biocomparables. A biosimilar product is defined in Section 351 of the Public Health Service (PHS) Act (42 USC § 262) as one which is 'highly similar to the reference product notwithstanding minor differences in clinically inactive components' and for which there are 'no clinically meaningful differences between the bio-logical product and the reference product in terms of safety, purity and potency of the product' [1]. The term 'biogeneric' is now obsolete because, unlike small-molecule generic drugs, a biosimilar is never identical to its reference product.A biosimilar etanercept, manufactured in China by CP Guojian Pharmaceutical Co., Ltd. (Shanghai), is already being mark