Biosimilars – How similar must they be?

28th April 2011

Category: Biosimilars

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By: Dr Daniel Galbraith, CSO,

The hype over the market for biosimilars remains buoyant; research indicates that the market is likely to be worth almost USD$20 Billion by 2014. This increase is in some part driven by the major Asian players who have well over one third of the market. This push is in many ways due to the strong domestic market for affordable healthcare. Europe has accepted biosimilars for over 5 years with the introduction of simple biologics in 2006. Collectively we are now moving to a much more challenging phase to introduce biosimilar versions of very complex monoclonals as these come off patent in the next few years.

The question of how similar a biosimilar must be to the innovator molecule is becoming crucially important. Technology today can allow us to investigate the molecular integrity of a single molecule and therefore analyzing two large protein molecules from two different manufacturers will always throw up differences; usually around the glycosylation pattern of the molecule. There is currently no model to describe “sameness” which is surely the core of the issue with these potent biologically active molecules. Our experience of cell based potency assays to measure the active drug has shown major discrepancies between batches of drug from the same manufacturer from the same production plant and from different plants. How can we expect a different manufacturer using a similar manufacturing process to achieve such a high level of similarity when manufacturers themselves cannot achieve this with licensed products? It is perhaps time to support the analysis of biologics over a number of batches to truly investigate how consistent these products are and from this analyse what should be expected from a biosimilar.