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Biosimilars: A Summary

4/4/2012 / by Dr. Evan Siegel


The much-anticipated FDA guidelines on the development and review of biosimilars have been recently released, and biologics developers are scrambling to interpret the resulting risks and opportunities.  This blog is the first in a series designed to provide orientation on the guidances, and key suggestions for their practical implementation.

The 2009 Biologics Price Competition and Innovation Act allows for the approval of “generic” biologics that are either biosimilar (able to be substituted for innovator products); or biosimilar “interchangeable” (therapeutic alternatives which can be directly substituted for the innovator product without consultation with the healthcare provider). FDA has interpreted this law in three guidances intended to provide aid to sponsors in dealing with the quality, nonclinical and clinical testing issues related to these products; however, there are many unanswered questions for biosimilars developers.

In some ways, the new guidances change nothing. Regulatory decisions on biologics are always based on a weight of evidence/totality of evidence approach. The extensive analytical, physicochemical and biological characterization suggested in the guidance for biosimilar products is the same as that required for new biological entities and in considerations of comparability. FDA is applying their significant experience with changes in the manufacture of originator biologic products (for example, the addition of new manufacturers, processes, and facilities) to hopeful “generic biologics” manufacturers. . FDA acknowledges different risk levels for determinations of biosimilarity, depending on the type of biologic involved, e.g.:

  • Simple monoclonal antibodies without side chains or conjugates
  • Recombinant vaccines
  • Multi-antigen products from expressed sources

Future blogs in this series will address how these FDA sensitivities and perspectives are likely to shape the development of specific classes of new biosimilar products.

The webcast “What You Must Know About FDA’s New Biosimilars Guidance” being presented on April 12, 2012, from 11:00 AM – 12:00 PST will present further information on this topic.  You can register for this seminar at