The generic drug industry is awaiting guidance from the US Food and Drug Administration (FDA) on how to proceed with testing and filing for approval of generic biotech drugs, following the European Commission's rejection last week of the world's first biogeneric.

How regulatory authorities deal with these types of drugs has become an important issue for the pharmaceutical industry, as several older biotech drugs near the end of their patent term. Agencies in the European Union and United States have been trying to hammer out regulations governing the approval of generic biotechnology drugs, which are more difficult to make than standard synthetic drugs. But last week's decision by the commission may be a signal that they aren't sure yet how to handle such products.

Sandoz, the world's second largest generics firm and a unit of Swiss pharmaceutical company Novartis AG, filed suit late last week against the European Commission for denying approval of its Omnitrop generic human growth hormone. The commission had cited filing irregularities as the reason for its decision.

The rejection of the drug came as something of a surprise following a recommendation for approval of the drug last year by the European Agency for the Evaluation of Medicinal Products' (EMEA) Committee for Proprietary Medicinal Products. Sandoz officials said late last week, according to media reports, that they believed they had used an appropriate pathway to file the drug and were engaged in an ongoing dialogue with the commission to resolve the dispute.

A major point of contention regarding impending regulations is the size and duration of clinical studies that would be required for approval of biogenerics. Generic firms have expressed a willingness to conduct smaller-scale studies to verify safety and efficacy of their products, but believe in certain instances that they shouldn't have to carry out the lengthier and more expensive required of a drug's original manufacturer.

This would be the case with generic human growth hormone and insulin products, which are relatively simple compounds to manufacture. However, the argument is a harder sell when it comes to more complex biotech drugs, such as Epogen, which is a larger molecule and is glycosylated.

Drug agencies are grappling with whether current regulations governing testing and the approval process for generic drugs will work with generic biotech products. The complex nature of biotech drugs may mean that regulators will have to evaluate the generics on an individual basis, rather than relying on a standard comparative method.

The FDA is currently working on a guidance document covering the application process for generic biotech drugs, or what the agency calls "follow-on biologics," and may take up the issue at a meeting in the near future. An FDA spokesperson told The Scientist that the draft guidance will be released sometime this year and "will describe current scientific methods for comparing products. However, it will not address legal issues such as access to specific prior research."

Representatives of the US generic drug industry have met with FDA officials and have suggested that the agency take a "reasonable, tiered approach" to the testing and approval process for biogenerics.

"We advocate a science-driven abbreviated approval pathway that accommodates products of various complexities and affords the FDA flexibility in data requirements to cover that range of complexities," Steve Bende, vice president of scientific affairs for the Arlington, Va.–based Generic Pharmaceutical Association, told The Scientist.

Meanwhile, Novartis has said that it would press ahead with development of several other biogeneric drugs in addition to Omnitrop.