Patent Update: Patent Validity Could Come Down to Clarity

A patent is intended to expand the public’s knowledge in a particular area of technology, and it must clearly convey exactly what the patent covers and what it does not. An individual learns that information by reading the patent’s claims, a relatively simple task unless a claim term is unclear, or, to use the legal term, indefinite. If an indefinite term is clarified in the body of the patent or in the patent’s record on file at the U.S. Patent and Trademark Office (USPTO), the term will not invalidate the patent. If it is not, however, the claim, and often the entire patent, can be deemed invalid. The standard, recently articulated by the U.S. Supreme Court, is that a patent is invalid for indefiniteness if its claims, read in light of the body of the patent and the patent’s record on file at the USPTO, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention. Two recent cases demonstrate how a failure to meet this standard can defeat a patent.

One case focused on the term average molecular weight used to characterize a polydisperse polymer. Teva Pharmaceuticals’ Patent No. 5,800,808 describes a method for making copaxone, a drug used to treat multiple sclerosis. Copaxone is a synthetic polypeptide analog of myelin basic protein known as copolymer-1. Copaxone is polydisperse but has a narrowly defined average molecular weight range of...