Biosimilar insulins – here they come

On September 10th 2014, the European Commission granted marketing authorisation for an insulin glargine, indicated to treat diabetes in adults, adolescents and children from the age of 2 years. This was the first insulin to be approved through the European Medicines Agency’s biosimilar pathway and followed ‘tentative approval’ for the same product from the Food and Drug Administration. The ‘tentative’ approval is the result of a patent infringement lawsuit in the US and anticipated delays almost certainly mean that Europe (and possibly the UK) will see the first launch.

So, what is the difference between a biosimilar and the generic products that have become so familiar? Generics are copies of small molecules derived from chemical manufacturing processes, and so are essentially identical to the original drug. In contrast, biosimilars are more complex peptides which, although they have an identical amino acid sequence, are made by biotechnological processes (such as yeast or bacterial fermentation). This means that the final 3-dimentional structure can be quite different to the original and so an identical pharmacological response cannot be guaranteed.

To be deemed ‘biosimilar’, the regulatory authorities require: similar pharmacokinetic and dynamic characteristics to the original; similar clinical efficacy; and no clinically meaningful differences in immunogenicity or adverse event profile from the reference product. These are much less stringent than would be required for a new diabetes therapy and do not, for example, include prohibitively expensive cardiovascular outcome studies.

Biosimilar products are not new, with sixteen biosimilars already approved in Europe across five product classes. Indeed, biosimilar glargine insulins have been commercially available for almost ten years but in regulatory areas which might be seen as less stringent than the US and EU. What seems certain is that biosimilars are about to join an increasingly complex UK basal insulin market, with at least three new products set to be launched over the coming 12 months….

Professor Steve Bain