Expert View: Lessons for industry following FDA backing of Neupogen biosimilar

January 7, 2015 witnessed the dawning of the era of biosimilars in the United States, writes Cecil Nick, Vice President - Technical, PAREXEL International. This was the day that the first product to be submitted under the new 351K procedure for biosimilars, Sandoz’ version of Neupogen (code named EP2006) was unanimously backed by the FDA Oncology Advisory Committee. However, it still remains to be seen what this decision will mean for the biosimilar industry moving forward.

While Neupogen contains a relatively simple protein, filgrastim, other products in the pipeline are far more complex (e.g. monoclonal antibodies and fusion proteins). These are an order of magnitude larger than filgrastim and have branched sugar chains of various forms attached to one or several of their amino acid side chains, as well as other side chain modifications, adding considerably to their complexity. These products therefore contain a whole family of slightly different molecular variants that can differ in proportion from one batch to the next; sometimes they have differed quite markedly following a change to the originator’s manufacturing process.

The challenge for the FDA and future Advisory Committees will be to know how much difference could be qualified as representing “minor differences in clinically inactive components” and imparting “no clinically meaningful differences in terms of the safety, purity, and potency” as required by the Biological, Price Competition and Innovation Act of 2009.