Biosimilar

A biosimilar (also known as follow-on biologic or subsequent entry biologic) is a biologic medical product that is almost an identical copy of an original product that is manufactured by a different company.^[1] Biosimilars are officially approved versions of original "innovator" products and can be manufactured when the original product's patent expires.^[2] Reference to the innovator product is an integral component of the approval.^[3]

Unlike with generic drugs of the more common small-molecule type, biologics generally exhibit high molecular complexity and may be quite sensitive to changes in manufacturing processes. Despite that heterogeneity, all biopharmaceuticals, including biosimilars, must maintain consistent quality and clinical performance throughout their lifecycle.^[4]

Drug-related authorities such as the European Medicines Agency (EMA) of the European Union, the United States Food and Drug Administration (FDA), and the Health Products and Food Branch of Health Canada hold their own guidance on requirements for demonstration of the similar nature of two biological products in terms of safety and efficacy. According to them, analytical studies demonstrate that the biological product is highly similar to the reference product, despite minor differences in clinically inactive components, animal studies (including the assessment of toxicity), and a clinical study or studies (including the assessment of immunogenicity and pharmacokinetics or pharmacodynamics). They are sufficient to demonstrate safety, purity, and potency in one or more appropriate conditions of use for which the reference product is licensed and is intended to be used and for which licensure is sought for the biological product.^{[citation needed]}

The World Health Organization (WHO) published its "Guidelines for the evaluation of similar biotherapeutic products (SBPs)" in 2009. The purpose of this guideline is to provide an international norm for evaluating biosimilars.^[5][6][7][8]

The EMA has granted marketing authorizations for more than 50 biosimilars since 2006. The first biosimilar of a monoclonal antibody to be approved worldwide was a biosimilar of infliximab in the EU in 2013.^[9] On March 6, 2015, the FDA approved the United States' first biosimilar product, the biosimilar of filgrastim called filgrastim-sndz (trade name Zarxio) by Sandoz.