The Risk of Using “Consisting Essentially of” in Patent ClaimsThe legal meaning of the transition language “consisting essentially of” is well-established in Federal Circuit case law and is generally construed to mean that the composition or formulation (a) necessarily includes the listed ingredients and (b) is open to unlisted ingredients that do not materially affect the basic and novel properties of the composition.  Similarly,

In a decision issued by the Federal Circuit on October 24, 2018, the court affirmed a finding by the Patent Trial and Appeal Board (PTAB) that a multiple sclerosis (MS) treatment claimed in A Morass of Possible Combinations Does Not Satisfy the Written Description Requirement under 35 U.S.C. § 112an application owned by FWP IP APS (FWP) was not supported by adequate written description under 35 U.S.C. § 112. While the