They write that recent years have seen the approvals, more so in the EU than the US, of follow-on biologic drugs. These products have been new formulations of recombinant therapeutic proteins, developed to compete with the marketed originator products. Intended to closely mimic the originator products in terms of chemistry and therapeutic properties, these so-called ‘biosimilar’ products were initially conceived to be developed according to abbreviated development programmes, presumably at a substantial cost saving to both the drug developer and the consumer. With several such products now recently approved, however, it has become clear that their development programmes have been quite extensive and not particularly abbreviated. Accordingly, cost savings to consumers appear to be relatively modest.

Dr Roth and Dr Fleischer note that though similarity of Omnitrope to Pfizer’s Genotropin (somatropin) was sufficient to allow ‘referenced’ Genotropin data, the products were not deemed ‘therapeutically equivalent’, and Omnitrope was not AB rated to Genotropin. Furthermore, for Sandoz’s and Hexal’s Epoetin alfa Hexal/ Binocrit/ Medice’s Abseamed compared to Janssen Cilag’s Eprex/Erypo, they find it interesting that the follow-on and reference erythropoietin products were concluded to be ‘biosimilar’ despite the demonstration of glycosylation differences between the active ingredients.

The authors conclude that Omnitrope and Valtropin biosimilar growth hormones, and a variety of follow-on recombinant erythropoietin approvals, constitute the initial acceptance of ‘biosimilar’ recombinant protein therapeutics. According to them, several long-held arguments have been sidestepped regarding the distinction between identical versus similar for the characterisation of follow-on protein products. However, based on review of the EU and FDA regulatory summaries for these products, it is not clear the extent to which drug development data could be considered ‘abbreviated’ in comparison to data typically obtained for a new recombinant growth hormone product. Given the substantive extent of preclinical and clinical data submitted in support of these applications, it is entirely inappropriate to refer to biosimilar products with the term ‘biogeneric’. Such products are clearly not generic by usual drug terminology, have very substantial product development data sets to support their approvals and are not currently designated as interchangeable with their originator products. It is also difficult to predict that savings to patients will approach the discount levels characteristic for typical generic drugs, although due to the very high cost of many recombinant protein therapeutics the absolute cost savings may prove substantial.

Reference:

Robert I. Roth and Nicholas M. Fleischer. A follow-on biological drug is not a biogeneric: Lessons from Omnitrope and Valtropin. Journal of Generic Medicines (2009) 6, 237-45. 2009 May.