Don’t Judge a Range by its Cover: Federal Circuit Sides with Patentee on Written Description Support

by Dennis Crouch

In a recent decision, the Federal Circuit held that a claimed range reciting narrower values than those described in the patent specification can still satisfy the written description requirement under 35 U.S.C. § 112(a). RAI Strategic Holdings, Inc. v. Philip Morris Prods. S.A., No. 22-1862 (Fed. Cir. Feb 9, 2024). Reversing a PTAB post-grant review decision, the court ruled that claims reciting a heating element with having a length of 75-85% of the disposable aerosol-forming substance had adequate written description support even though the specification only described broader ranges, such as “about 75% to about 125%.” Id.

The claims at issue related to electrically-heated smoking articles. Philip Morris argued that while the patent described heating element lengths relative to the disposable substance ranging from 75-125% and 85-115%, it never described the specific range of 75-85% as required by claims 10 and 27. The PTAB agreed, finding that “[n]o described range contains an upper limit of ‘about 85%’” as claimed. The claim had been added in a continuation application via preliminary amendment and was never directly rejected during prosecution.  But, there was no particular reason why that limitation was critical or important. In fact, the limitation at issue is found in dependent claims and were not mentioned by the examiner in her reasons for allowance.

Reversal: On appeal, the Federal Circuit relied heavily on In re Wertheim, 541 F.2d 257 (C.C.P.A. 1976), which established important guiding principles for analyzing written description support of claimed numerical ranges.  In Wertheim, the court considered whether a claimed range of “between 35% and 60%” soluble coffee solids had adequate written description support when the specification disclosed a broader range of “25 to 60%” solids. The court held that the claimed narrower range did have sufficient written description support, explaining:

In the context of this invention, in light of the description of the invention as employing solids contents within the range of 25-60% along with specific embodiments of 36% and 50%, we are of the opinion that, as a factual matter, persons skilled in the art would consider processes employing a 35-60% solids content range to be part of appellants’ invention and would be led by the Swiss disclosure so to conclude.

Wertheim. The court emphasized that “[m]ere comparison of ranges is not enough, nor are mechanical rules a substitute for an analysis of each case on its facts.” Ultimately, the issue was “whether the invention appellants seek to protect by their claims is part of the invention that appellants have described as theirs in the specification.” Because the court found no evidence that the disclosed broader range and claimed narrower range “pertain[ed] to different inventions,” it held that the claimed range had adequate written description support.

Applying this standard, the Federal Circuit held that Philip Morris had failed to show that the disclosed range of 75-125% and the claimed range of 75-85% pertained to different inventions. Given the predictable nature of the electro-mechanical smoking device and the specification’s teaching of the claimed end points (75% and 85%), the court found no reasonable factfinder could conclude that the narrower claimed range of heating element lengths fell outside the inventor’s possession.  The decision  attempted to distinguish In re Baird, 348 F.2d 974 (C.C.P.A. 1965), and Indivior UK Ltd. v. Dr. Reddy’s Labs. S.A., 18 F.4th 1323 (Fed. Cir. 2021).  In those cases, the court found the narrower claimed ranges resulted in inventions different from what was described in the specifications.  Indivior is quite close because the specification did disclose two endpoints of  48.2 wt % and 58.6 wt % of film forming polymer. But the court concluded that the claimed range from 48.2 to 58.6 was not disclosed — finding a “lack of persuasive evidence that a skilled artisan would have understood the application as disclosing an invention with the range between these endpoints.”  In distinguishing Indivior, the court here highlighted inconsistent statements in the Indivior specification regarding the range. Despite being so similar to Invidior, the Federal Circuit concluded that the PTAB’s decision lacked evidentiary support — despite specific expert testimony on point.

In all these cases, the court has repeatedly stated that the written description analysis is done on a case-by-case basis and that “broadly articulated rules are particularly inappropriate in this area.”  Thus, one key takeaway here is that this case-by-case approach makes it difficult to predict whether a particular amended or added range will be deemed adequately supported.

Although the patentee won on these two dependent claims (Claims 10 and 27), the panel affirmed the obviousness rejection of all the remaining claims.  Additionally, the Board did not decide the obviousness issue for claims 10 and 27 since it had already found them lacking written description. On remand the board may take up that issue. And, the language of the appellate decision will not help the patentee on remand. In particular, the Court found the written description support for this new range since it was the same invention as the other ranges provided. Result being that this my be more of a pyrrhic victory for the patentee.

On obviousness, the Federal Circuit affirmed the Board’s decision that the remaining claims of RAI’s patent would have been obvious over the combination of two references, Robinson and Greim. The key issue on appeal was whether there was substantial evidence to support the Board’s finding that a skilled artisan would have been motivated to combine the heating element taught in Greim with the smoking article disclosed in Robinson. The Federal Circuit held there was substantial evidence of a motivation to combine based on the “design choice” language in Robinson itself inviting improvements to the heating element, as well as Greim’s teachings that its heater design provided flexibility and advantages over other heaters.

For all the embodiments described above, the selection of battery and resistance heating elements can vary, and can be a matter of design choice. … Selection of the power source and resistance heating elements can be a matter of design choice, and will be readily apparent to one skilled in the art of design and manufacture of electrical resistance heating systems.

Panel: Judges Chen; Stoll and Cunningham
OpinionBy: Judge Stoll

Arguing counsel: Gregory A. Castanias of Jones Day for RAI Strategic Holdings, Inc.; Jonathan M. Strang of Latham Watkins for Philip Morris Products S.A.

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