New England Journal of Medicine
August 4, 2011  Vol. 365 No. 5
http://content.nejm.org/current.shtml

Perspectives
Developing the Nation’s Biosimilars Program
S. Kozlowski, J. Woodcock, K. Midthun, and R. Behrman Sherman
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Extract
Biologic products developed over the past three decades and approved by the Food and Drug Administration (FDA) now provide important therapeutic options for a variety of serious clinical conditions (see graph Numbers of FDA-Approved Biologic Products of Various Types Available for Treating or Preventing Various Conditions.). Therapeutic biologics such as genetically engineered recombinant proteins and monoclonal antibodies represent a large portion of newly approved therapies for conditions such as chronic inflammatory diseases and cancer. Biologic enzyme-replacement therapies provide clinical benefits in previously untreatable genetic disorders. Although typically more structurally complex than the small-molecule drugs more prevalent in today’s market, biologics vary in complexity from cellular therapies to small, highly purified proteins. Unfortunately, access to such products may be limited, not infrequently because of their cost….