Manufacturing history of etanercept (Enbrel): Consistency of product quality through major process revisions.

Etanercept (ETN) (Enbrel®) is a soluble protein that binds to, and specifically inhibits, tumor necrosis factor (TNF), a proinflammatory cytokine. ETN is synthesized in Chinese hamster ovary cells by recombinant DNA technology as a fusion protein, with a fully human TNFRII ectodomain linked to the Fc portion of human IgG1. Successful manufacture of biologics, such as ETN, requires sophisticated process and product understanding, as well as meticulous control of operations to maintain product consistency.

Variability of intended copies for etanercept (Enbrel®): Data on multiple batches of seven products.

Fusion protein and monoclonal antibody-based tumor necrosis factor (TNF) inhibitors represent established treatment options for a range of inflammatory diseases. Regulatory authorities have outlined the structural characterization and clinical assessments necessary to establish biosimilarity of a new biotherapeutic product with the innovator biologic drug. Biologic products that would not meet the minimum World Health Organization's standard for evaluation of similar biotherapeutic products are available in some countries; in some cases relevant data to assess biosimilarity and appropriate regulatory approval pathways are lacking.

Differentiating biosimilarity and comparability in biotherapeutics.

The manufacture of biologics is a complex process involving numerous steps. Over time, differences may arise as a result of planned changes to the manufacturing processes of a biologic from the same manufacturer. Comparability is the regulatory process that outlines the scope of an assessment required of an already licensed biologic after a manufacturing process change made by the same manufacturer.