Patent Law Practice Center

Navigating the Best Mode Requirement

            The Patent Act provides that the patent specification “shall set forth the best mode contemplated by the inventor of carrying out his invention.”[1]  This requirement, also known as the best mode requirement, is in essence a quid pro quo with the inventor.  In return for granting the right to exclude others from making or using a patented invention, the inventor must disclose or conversely not conceal from the public the preferred embodiment.  But, what constitutes the preferred embodiment, how much information actually needs to be disclosed, what can be withheld and what happens when the inventor is not aware of the best mode?  The recent case law provides some answers to these questions, but also raises other concerns, especially as we enter the brave new era of biosimilars and the inevitable wave of litigation that will likely ensue.

            In order to satisfy the best mode requirement, the inventor must disclose the preferred embodiment of his invention as well as any preferences that could materially affect the invention.[2]  The first step in a best mode inquiry begins, as is always the case with patent law, with the claims.[3]  This past March the Federal Circuit handed down a decision in Ajinomoto Co. v. ITC where the scope of the claims created a problem for the inventors.[4] (more…)