Fitch Ratings has been giving its views on the US Food and Drug Administration's draft guidance for biosimilars, saying it has created a reasonable framework for generic biologics.

The agency has laid out its position in three documents which are designed to "help industry develop biosimilar versions of currently-approved biological products, which can enhance competition and may lead to better patient access and lower cost to consumers”, according to Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research. She added that "when it comes to getting new biosimilar products on the market, FDA has taken an innovative approach to supporting their development at every step of the process".

The first document describes a risk-based “totality-of-the-evidence” approach that the FDA intends to use to evaluate the data and information submitted in support of a determination of biosimilarity of the proposed product to the original. The agency recommends a "stepwise" approach.

The second guidance provides "an overview of analytical factors to consider" and stresses the importance of "extensive analytical, physico-chemical and biological characterisation in demonstrating that the proposed biosimilar…is highly similar to the reference product notwithstanding minor differences in clinically inactive components".

The third part comes in a 'questions and answers' format which addresses questions that may arise in the early stages of product development, such as how to request meetings with the FDA, addressing differences in formulation from the reference product and how to request exclusivity.

Among the responses to the pathway set out by the FDA, Fitch Ratings believes it will provide the necessary framework to allow drug companies to develop generics of biologics.

The ratings agency notes that firms must satisfy proposed regulations with human clinical information to prove equivalence to the originator medicine on a case-by-case basis. Secondly, once it gains approval, the multisource drug must prove interchangeable with the original medicine and Fitch notes thats interchangeable drugs require much less investment to capture market share.

The global market for biosimilars was just $311 million in 2010, which was mainly generated in Europe, and is expected to increase to $2-$2.5 billion. Fitch says the expertise gained by the largest players (Teva, Hospira and Sandoz) "via the European marketplace will offer drug makers a running start in the USA".

However it makes special mention of branded players such as Amgen, which has established a partnership with Watson to develop generic versions of cancer drugs, Baxter (which has teamed up with Momenta Pharmaceuticals to develop six biogenerics) and Biogen Idec, which has set up a new biosimilar joint venture with Samsung.