Written Description and Creating Ranges from Examples

April 7, 2022

At the close of last year, the Federal Circuit affirmed a decision by the PTAB in IPR2019-00329 that a claimed range created from examples was not patentable because it lacked written description in the application as filed. In its decision the PTAB “second guessed” an examiner’s ex Parte decision that the claimed range had written description in the application as filed.  Written description was at issue because the patent challenged, U.S. Patent 9,687,454 (‘454), filed January 6, 2016, needed benefit of its parent application serial number 12/537,571 published on February 10, 2011, as 2011/0033541 (‘541), to avoid ‘541 from being prior art otherwise, most of the ‘454 claims were anticipated by ‘541. The ‘454 claim 1 is directed to a mucoadhesive film comprising about 40 wt.% to about 60 wt.% of a water-soluble polymeric matrix and claim 7 to a range of from about 48.2 wt.% to about 58.6 wt.%. Neither range was found in the ‘454 patent as filed; the claims were added during prosecution. The ‘454 describes the film as “may contain any desired level of self-supporting film forming polymer”; in “one embodiment, the film forming composition” may be at least 25 weight per cent of the composition; alternatively, at least 50 weight per cent of the composition. No upper limit was described.

The range of 40 wt.% to 60 wt.% was not described.  Indivior pointed to examples where one could calculate the amount of polymer in one example 48.2 wt.% and in another 58.6 wt.% as written description of the range. Indivior relied upon In re Wertheim, 541 F.2d 257 (CCPA 1976) to support the concept the range found written description. However, Wertheim, unlike Indivior, described a range of 25 to 60% and exemplified 36% and 50% which the court held to support the claimed range of 35 to 60% added by amendment. The Wertheim court noted that the range of claim 35 to 60% was within the expressed range of 25% to 60% found in the specification. The Wertheim court found claims amended to recite “at least 35%” lacked written description because it reads on embodiments outside of the range described in the specification.

The Court also noted that the claimed range was inconsistent with the teaching “any desired level.”  Further, Indivior when it amended the claims referred to a portion of the specification different from that relied upon in the IPR, a portion which Indivior admitted did not describe the claimed range. Finally, the new range included examples which did not achieve the objective of the invention, bioequivalency with oral Suboxone,® the objective of ‘454.

One must also consider that the examples provided no support for 40 wt.% as the example was at 48.2 wt.%. Normal rounding rules do not allow for rounding from 48.2 wt. % to 40 wt. %. In contrast, 36% can be rounder to 35% using normal mathematical rules. Further, in Indivior every other claim limitation had both lower and upper limits in the specification, the polymer did not. Also, Indivior’s briefing ignored the significant number of Federal Circuit cases which considered the creation of ranges to lack written description. The Court noted that where “[t]he disclosure of a broad range of values does not by itself provide written description support for a particular value within that range.” Gen. Hosp. Corp. v. Sienna Biopharm., Inc., 888 F.3d 1368, 1372 (Fed. Cir. 2018).

Practice Tip

Taking Wertheim and Indivior and the intervening Federal Circuit case law leads to the conclusion that one must approach the writing of a patent specification with the care one would give to writing a contract.  There are no short cuts. Where one is claiming a composition, place lower and upper limits on the content of each component of the composition, preferably a nested group presenting an ever-narrowing range. Do not assume that content of any component in the composition is not important and need not be described completely.