Written Description Remains Critical to Patents

by Audrey A. Millemann
The IP Law Blog

There are many requirements for obtaining a patent.  One of those is the written description requirement.  Pursuant to 35 U.S.C. §112(a), the patent must describe the invention in writing.  If the written description requirement is not met, the patent won’t be granted.  If the patent has already been issued, it can be invalidated for failure to satisfy the written description requirement.  Recently, in Juno Therapeutics, Inc. v. Kite Pharma, Inc., 2021 U.S. App. LexIs 25706 (Fed. Cir. 2021), a damage award of $1.2 billion for patent infringement was reversed for just this reason.

Juno owned a patent covering the genetic material that codes for compounds called chimeric antigen receptors (CAR), used in treating cancer through immunotherapy.  In CAR T-cell therapy, the patient’s T-cells are reprogrammed to produce a specific antigen receptor that recognizes and blocks the targeted cancer cells.  The reprogramming is accomplished by transferring genetic material (nucleic acids) into the T-cells so that the cells produce the antigen receptor.  Juno’s patent covered the nucleic acids that coded for the binding elements of two antigen receptors, one for lymphoma cells and one for prostate cancer cells.

Kite developed an immunotherapy technology using CAR to target lymphoma and leukemia cells.  Juno sued Kite for patent infringement, alleging that Kite’s immunotherapy technology infringed Juno’s patent.  Kite filed counterclaims for non-infringement and invalidity, including on the grounds that the written description requirement was not met.

At trial, the jury found that Kite was liable to Juno for willful patent infringement, and that Kite owed Juno $585 million in damages and a running royalty of 27.6%.  The jury found that Kite had not proven its claim that the patent failed to satisfied the written description requirement or that it was not enabled.  After trial, the district court updated the damage amount to $778 million and enhanced the damages by 50% for willfulness for a total of $1.2 billion, and awarded the running royalty of 27.6%.  Kite appealed.

The Federal Circuit Court of Appeals reversed, holding that the patent was invalid as it did not satisfy the written description requirement.  The court explained that the key to satisfying the written description requirement is disclosure.  The requirement is met if the description “reasonable conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date.”  The sufficiency of the written description depends on the nature and scope of the invention and on the scientific knowledge in the field at the time.  A wish or a plan does not satisfy the requirement.  In patents involving chemical inventions, the written description must define the chemical in a precise way, either by structure, form, or name.

Kite argued that Juno’s claims failed to satisfy the written description requirement because the patent did not disclose representative species of the genus of compounds or common structural features of the genus.  Kite contended that the claims covered “millions of billions” of chemical candidates, but that, of these, only a tiny number would satisfy the binding limitations for a targeted cancer cell as claimed.  Kite also argued that this field was unpredictable, meaning that a higher level of specificity was necessary in order to satisfy the written description requirement.

The court agreed with Kite, holding that no reasonable jury could find that Juno was in possession of the claimed invention.  The court stated that the patent did not list a representative sample of the species in the genus, or even the characteristics of the genus.  According to the court:

“To satisfy the written description requirement, the patent needed to demonstrate to a skilled artisan that the inventors possessed and disclosed in their filing the particular species of [compounds] that would bind to a representative number of targets.”

The court also explained the patent did not disclose the structural features that were common to the genus of compounds.  “Simply put, the …patent claims a problem to be solved while claiming all solutions to it….covering any compound later actually invented and determined to fall within the claim’s functional boundaries…”  Juno’s written description would not permit a person skilled in the art to know what compounds other than the examples would work in the invention.

Juno lost a $1.2 billion damage award for lack of a written description.  This case is a reminder to patent applicants to make sure they thoroughly describe what their invention is such that they demonstrate that they actually were in possession of the invention when they file their application.