FDA head hints at biogenerics

He said that the agency is currently looking into the legality of approving 'biogenerics' under federal law, and would be publishing initial proposals on this issue in the next few months.

Some of the biggest-selling biological drugs developed during the first phase of the biotechnology revolution in the 1980s - including human growth hormone (hGH) and insulin - are set to lose patent protection in the US in 2005 and beyond.

Governments are keen to get biogenerics approved to reduce the cost burden of these drugs, which tend to be very expensive compared to small-molecule agents, but the complexity of their manufacture means that it can be difficult to ensure that changes in production will not lead to alterations in the final resulting medicine.

In Europe, the generics company Sandoz has already filed for approval of a generic version of hGH called Omnitrop (somatropin), marking the first generic assault on a market valued at $30 billion and growing at 10 per cent a year. The company was able to submit its application after the European Commission cleared a regulatory route for biogenerics in June.

Meanwhile, Sandoz is gearing up to file for approval of Omnitrop in the US early next year, so the FDA​ will have to deal with these issues sooner rather than later.

McClellan said he was in agreement with the principle that some biologics could be approved on the basis of toxicology and bioequivalence data - without the need for extensive efficacy trials - but cautioned this may not apply in all cases as some products have extremely complex structures that are hard to make.

Meanwhile, industry observers are still concerned that there remain plenty of legal and technical obstacles to approving generic biologics in the US. For example, in order to give them a so-called AB bioequivalence rating - allowing substitution of a branded drug for a generic - changes to some fundamental legislation, including the Hatch-Waxman act, will likely be required.