Sandoz starts clinicals on biosimilar Rituxan – is the field already getting crowded?

In Europe, guidelines for the development of monoclonal biosimilars have been released for consultation and are expected to be finalised this year, providing clarity to manufacturers. In the US, there are currently no guidelines and the FDA is still mulling over the input that it got from a two-day meeting of interested parties in November 2010. As a result, the two front-runners in biosimilars, Teva and Sandoz, are taking divergent approaches to the US market, which we would characterise as the pragmatic and the scientific. Sandoz clearly believes that biosimilars can be shown to be sufficiently similar to the originator to be considered interchangeable and hence it is likely to try to anticipate the requirements of the FDA in an effort to demonstrate this. Teva very probably believes the same, but is more interested in having a product on the market than in scientific principles and is therefore aiming at the BLA route for its products. This also avoids having to share information about its production methods with originators. The risk of this is that Sandoz will turn out to be correct and that Teva will be left with a branded product with low sales while Sandoz gets a substitutable one that takes half the market, but this risk is low. The FDA is inherently cautious, which makes it very unlikely that it would accept that biosimilars can be interchangeable without substantial clinical data to back this up. Plus, there is nothing to stop Teva working on both pathways at once, just in case. In the US, therefore, it still seems probable that biosimilars will turn out to be a low volume but high price affair, whereas in Europe it could easily be the opposite (or, worse, low volumes and low prices as well), once the fourth or fifth version of the same Mab comes to market.