Swiss biopharmaceutical company BioPartners has been granted marketing approval by the European Medicines Agency (EMEA) for Valtropin, a biosimilar version of human growth hormone.

Valtropin (somatropin) is only the second biosimilar to be cleared for marketing in Europe, and follows in the wake of Omnitrope, developed by Novartis' generics subsidiary Sandoz, which got a green light by the EMEA last month. It has been approved for the treatment of human growth deficiency in children and Turner’s syndrome, and BioPartners said it aims to launch it before year-end.

The growth hormone market is estimated to be worth about $2.6 billion worldwide and while Omnitrope is not expected to be a significant new product for a company the size of Novartis, for privately-held BioPartners the approval is a transforming event.

BioPartners also has a biosimilar version of interferon alpha for hepatitis filed with the EMEA, and has a sustained-release formulation of Valtropin in Phase III clinical development.

The EMEA is leading efforts by regulators to help bring copycat versions of off-patent biologic drugs – sometimes referred to as biogenerics – to the marketplace. Biologic drugs with sales of more than $20 billion are at immediate risk of generic competition, and could help reduce the cost of delivering these therapies to cash-strapped health system, although because of high manufacturing costs savings are expected to be limited - perhaps coming in 10% to 20% lower than brandname drugs initially.

In the USA, biosimilars – also known as 'follow-on biologics' - are not expected to reach the market until at least 2009, although Sandoz is suing the Food and Drug Administration to try to force it to act on a stalled marketing application for Omnitrope.

Last month, a federal judge ordered the FDA to deliver a verdict on the dossier, which was filed in July 2003, and ordered the FDA to move ahead with setting out a clear regulatory framework for this type of product in the US market.