Introduction

The development of biosimilar biologic drugs is a major area of development for biopharmaceutical companies. Biologic drugs differ from small-molecule medications because they are typically large proteins derived from living organisms and have different requirements for initial FDA approval. Many of these medications are expensive specialty medications. Examples include cancer therapies, autoimmune disease therapies, and blood components that consume a large share of health care costs. For example, one of the most expensive drugs in the United States is the biologic medication Soliris (eculizumab). Soliris is an antibody that treats a disease that destroys red blood cells at night and costs over $400,000 per year. 

While small-molecule medications can also be expensive, it is easier to manufacture generic versions of small-molecules after their patent expires. It may seem obvious to fix this problem for biologics by creating generic biologic products once the original branded biologic expires. However, there are two primary reasons this is not possible. First, as previously mentioned, biologics have different requirements for approval compared to small molecules and their generics. Second, since they are biologics and not small-molecules, they do not meet the FDA definition of a generic and therefore cannot be approved through an Abbreviated New Drug Application (ANDA) that is used to file for small-molecule generics. The absence of policies and procedures to develop and approve lower-cost biologic products (after patent exclusivity has expired) has led to the development of biosimilars. These medications are not generics, but rather defined as products that are highly similar to a previously approved biologic “reference” or “originator” product.

Although there are FDA-approved biologic medications meeting the definition for “biosimilar” drugs, none have undergone evaluation by the FDA through the biosimilar approval pathway. Currently, approved biosimilars (for example, Neupogen and Granix) were filed under the traditional pathway of approval for biologic medications which requires a New Drug Application (NDA) and Biologic License Application (BLA). Other countries (Europe and Asia) have established and implemented specific guidelines for approval of biosimilar  medications and have seen reductions in health care costs as a result. The FDA also recognizes the advantages of creating a market for companies to develop biosimilar medications, hoping that both patients and companies will benefit. In July 2014, biosimilar manufacturer Sandoz made history by becoming the first company to submit an application for approval of a biologic product under the abbreviated biosimilar pathway. The FDA has yet to finalize guidelines and requirements for industry to follow when submitting under this abbreviated pathway. Many expect this filing will have a significant influence on finalizing the requirements for submission of biosimilars.

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