One of the requirements for obtaining a patent is the written description requirement – the specification must include a written description of the invention. 35 U.S.C §112(a).  This requirement means that the specification must fully disclose what the invention is.  The purpose of the written description requirement is to demonstrate to persons skilled in the art of the invention that the inventor had possession of the invention at the time the application was filed, i.e., that the inventor actually invented the invention.  In exchange for the limited “monopoly” that a patent provides to its owner, the public is entitled to know the scope of the patent.  The public must know what the patent owner can protect with the patent.

Another requirement of a patent is that it must be enabled – the patent must describe to a person skilled in the art of the invention how to make and use the invention.

Patents are not frequently invalidated for failure to satisfy the written description requirement or for lack of enablement.  Instead, patents are most commonly invalidated on the grounds that they lack novelty or are obvious over the prior art, and most of the cases deal with these requirements.

The written description requirement is an important one, however, as demonstrated by the Federal Circuit Court of Appeals’ recent invalidation of two pharmaceutical patents on that ground.

In Nuvo Pharmaceuticals Designated Activity Co. v Reddy’s Laboratories Inc., 2019 U.S. App. LEXIS 14345 (May 15, 2019), Nuvo sued several defendants for infringing two patents for a drug called Vimovo.  Vimovo was a combination drug which included a non-steroidal anti-inflammatory drug (NSAID) to treat pain, a coating around the NSAID to prevent its release until the pH had increased to about 3.5, and a proton pump inhibitor (PPI) (which was coated to prevent its degradation) to raise the pH and to reduce acid in the stomach.  The defendants were pharmaceutical companies who planned to market generic versions of Vimovo.

The defendants stipulated to infringement of the patents, but contended that the patents were invalid for several reasons, including for failure to satisfy the written description requirement.  At a bench trial, the district court held that the patents were valid.

On appeal to the Federal Circuit, the defendants argued that the patents’ claims for an effective drug that included an uncoated PPI were invalid because the patents did not describe the efficacy of the drug with the uncoated PPI.  Nuvo raised several arguments, primarily contending that the specification did not need to show the effective amount of the uncoated PPI.  Nuvo also presented expert testimony that its specification satisfied the written description requirement.

The Federal Circuit rejected all of Nuvo’s arguments.  The court explained that the written description requirement is not met by simply including the claim verbatim in the specification.  The court noted that the inventor does not need to include experimental data in the specification to show efficacy, or even conduct any testing; does not need to explain why the drug works; and does not need to reduce the invention to practice.  However, the specification must include a written description adequate to show that the inventor was in possession of the invention (a constructive reduction to practice).  The court stated:

“Patents are not rewarded for mere searches, but are intended to compensate their successful completion…That is why the written description requirement incentivizes ‘actual invention,’…and thus ‘a mere wish or plan for obtaining the claimed invention is not adequate written description’…[citations omitted].”

The court held that Nuvo’s patents were “fatally flawed.”  The specifications were nothing more “than a mere wish or hope that uncoated PPI would work…”

The court further rejected Nuvo’s argument that the patents satisfied the enablement requirement and therefore also satisfied the written description requirement.  The two requirements are “separate and distinct;” both requirements must be met.  The court explained:

“The purpose of the written description requirement is broader than to merely explain how to ‘make and use the invention’…The focus of the written description requirement is instead on whether the specification notifies the public about the boundaries and scope of the claimed invention and shows that the inventor possessed all the aspects of the claimed invention.”

The written description requirement is a key requirement for obtaining a patent.  In essence, it is the first requirement: the inventor must be able to state what it is they invented, and be able to describe the invention itself.  The requirement should not be assumed, overlooked, or minimized, at the risk of the losing the patent later on.