Intellectual Property & Technology Law Journal
Antibodies are proteins produced in nature by the immune system and used frequently in biologic therapies for their ability to bind and alter signaling pathways involved in various diseases such as cancer, infection, and inflammation. Antibodies recognize particular target agents, called "antigens," which are bound via variable domains at the end of the antibody. The specific portion of an antigen bound by an antibody is referred to as an "epitope." Two antibodies that bind the same or similar epitopes may compete for binding, meaning the presence of the first antibody bound to the antigen prevents the second antibody from accessing and binding its epitope on the same antigen.
When drafting an antibody patent application, a question often arises of whether to include claims that define the antibody by its epitope or competitive binding properties, in addition to claiming the antibody by its amino acid sequence. The answer, as with most questions in patent law, is that it depends. It depends, mainly, on the amount of data available at the time of filing, or the likelihood that sufficient data will be generated later that could support an epitope claim. While it is still an open question of how well a claim to any antibody defined by its epitope or competitive binding properties will stand up to challenge, a claim supported by extensive testing might significantly improve the chances of validity and, at the same time, sizably expand the scope of protection around important commercial products. In this article, Finnegan attorneys Jeffrey M. Jacobstein, Amanda K. Murphy, and Leslie A. McDonell discuss the Amgen Inc. et al v. Sanofi case, which underscores this point.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
