Federal Circuit Finds Written Description Support for Narrow Claim Range via Disclosure of Broader Ranges, Vacates PTAB Decision

March 15, 2024

Reading Time : 3 min

The Federal Circuit recently vacated a PTAB decision that claims of an “e-cigarette” patent were unpatentable for lack of written description under 35 U.S.C. § 112. The question on appeal was whether a claimed range was adequately supported by the disclosure of broader ranges. In this case, the answer was “yes.”

The patent-at-issue—RAI Strategic Holdings, Inc.’s U.S. Patent No. 10,492,542—generally relates to “electrically powered smoking articles,” or “e-cigarettes.”  In 2020, Philip Morris Products S.A. sought post grant review of the ’542 Patent, asserting (among other grounds) that dependent claims 10 and 27 were invalid for lack of written description. Those claims recited, in relevant part, a “heating member” with “a length of about 75% to about 85% of a length of [a] disposable aerosol forming substance.”

At the PTAB, Philip Morris argued that the claimed range of “about 75% to about 85%” lacked written description support because the specification disclosed only ranges of 75–125%, 80–120%, 85–115% and 90–110%. According to Philip Morris and its expert, those disclosures did not support the claimed range because (1) they were all “substantially narrower” than the claimed range, (2) none of them recited “an upper limit of 85%” as claimed and (3) they all “centered on” 100%, unlike the claim, which centered on 80%. RAI countered that the disclosed ranges of 75–125% and 85–115% together supported the claim because they expressly include “both ends of the claim range,” i.e., 75% and 85%. Nonetheless, the PTAB agreed with Philip Morris and found the claims unpatentable. RAI appealed.

On appeal, the Federal Circuit vacated the PTAB’s decision, concluding that the facts more closely aligned with decisions finding written description support for a claim range. In re Wertheim, for example, held that the disclosure of coffee grounds with “25% to 60%” solid coffee extract supported a claim range of “between 35% and 60%.” 541 F.2d 257 (C.C.P.A. 1976). Importantly, the Wertheim court found no evidence that the “broad described range pertain[ed] to a different invention than the narrower (and subsumed) claimed range.” 

Here, the Federal Circuit likewise saw no evidence—including from Philip Morris’s expert—that the disclosed ranges were “different inventions” than the claimed range. That is, “nothing in the specification indicate[d] that changing the length of the heating member changes the invention, whether as to operability, effectiveness, or any other parameter.” Although the specification did not disclose the claimed range, it did expressly disclose both endpoints of the claimed range. Moreover, the “predictability of electro-mechanical inventions” such as e-cigarettes further supported the Federal Circuit’s ruling, as predictable art requires “a lower level of detail” to satisfy written description than unpredictable art.

The Court also grappled with cases that found a lack of written description on somewhat similar facts, most notably Indivior UK Ltd. v. Dr. Reddy’s Laboratories S.A., 18 F. 4th 1323 (Fed. Cir. 2021). The Indivior claims recited a therapeutic film comprising “about 48.2 wt % to about 58.6 wt %” polymers. The specification, meanwhile, disclosed a table with a 48.2 wt % polymer and a 58.6 wt % polymer—the endpoints of the claimed range. However, unlike the present case, in Indivior, there was a “lack of persuasive evidence that a skilled artisan would have understood the application as disclosing an invention with the range between these endpoints.” The Indivior patent also differed in that it involved an unpredictable art and the specification made “inconsistent statements regarding the desired amount of polymer.”

Finally, in coming to its conclusion, the Federal Circuit repeatedly emphasized that written description is assessed on a case-by-case basis and that “broadly articulated rules are particularly inappropriate in this area.” Instead, one must consider the technology at issue, the predictability of the art, the complexity of the claim limitation and the knowledge gained by a person skilled in the art reading the specification. Thus, while the Court relied on prior cases for support and guidance, its ruling was ultimately “based on the unique facts of this case.”

Practice Tip: Although claims directed to ranges that are not explicitly disclosed in the specification may be susceptible to written description attacks, particularly in arts regarded as unpredictable, the RAI case shows that such claims may be adequately supported if the disclosed and claim ranges are not shown to be “different inventions.” Parties asserting and defending against such attacks should focus arguments on the specific facts of the case and, if possible, provide expert testimony that addresses how exactly the claim range is (or is not) a different invention from the ranges disclosed in the patent.

RAI Strategic Holdings, Inc. v. Philip Morris Products S.A., No. 22-1862 (Fed. Cir. Feb. 9, 2024)

Share This Insight

Previous Entries

IP Newsflash

August 11, 2025

In considering a motion to dismiss infringement claims for two related patents, the District of Massachusetts recently held that pre-suit knowledge of a “parent” patent, without more, is insufficient to establish pre-suit knowledge of the “child” patent for purposes of indirect and willful infringement.

...

Read More

IP Newsflash

August 8, 2025

Following a jury verdict finding trade secret misappropriation, the District Court for the District of Massachusetts granted-in-part a plaintiff’s motion for a permanent injunction to prohibit defendants from using plaintiff’s trade secrets. The district court further required defendants to reassign to plaintiff patents and patent applications that disclosed or were derived from plaintiff’s trade secrets as part of its equitable relief.

...

Read More

IP Newsflash

August 6, 2025

In ruling on a recent motion to strike, a judge in the Eastern District of Texas permitted a damages expert to rely on a damages theory based on defendant’s “avoided costs,” holding that this theory did not run afoul of the “entire market value rule.”

...

Read More

IP Newsflash

August 5, 2025

The Federal Circuit recently vacated a decision by the Patent Trial and Appeal Board after concluding that the board’s analysis of licensing evidence offered as a secondary consideration of nonobviousness constituted legal error and was not supported by substantial evidence. According to the court, the board applied a more exacting and improperly heightened nexus standard than is required by law for license evidence.

...

Read More

IP Newsflash

August 5, 2025

A Northern District of California judge recently granted a motion to reconsider his summary judgment ruling that defendant was barred from raising certain “device art” due to IPR estoppel under 35 U.S.C. § 315(e)(2). In the original ruling, the judge adopted the broader rule that IPR estoppel applies to device art that is “materially identical” to patents or printed publications that petitioners raised, or could have raised, in an IPR. Following that ruling, however, the Federal Circuit issued its Ingenico decision adopting the narrower view that IPR estoppel applies only to “grounds” based on patents and printed publications and not to device-based grounds. Citing Ingenico as a “change of law,” defendant moved for reconsideration of the court’s ruling, and the court granted the motion.

...

Read More

IP Newsflash

August 5, 2025

In a recent decision designated as Informative, the USPTO Director determined that the Patent Trial and Appeal Board abused its discretion by instituting two inter partes review proceedings challenging the same patent, based on petitions advancing different constructions of the same claim term. The Director expressed concerns that permitting multiple petitions based on alternative claim constructions effectively circumvents word count limitations, strains board resources, and undermines procedural efficiency.

...

Read More

IP Newsflash

July 25, 2025

Earlier this year, the Federal Circuit’s decision in Qualcomm Inc. v. Apple Inc. (Qualcomm II) raised questions about the extent to which petitioners can rely on applicant admitted prior art (“AAPA”) in inter partes review proceedings.  The Federal Circuit’s recent decision in Shockwave Medical, Inc. v. Cardiovascular Sys., Inc. largely cabins the Qualcomm II decision to its particular facts and makes clear that AAPA can be used as evidence of background knowledge as part of an obviousness argument.

...

Read More

IP Newsflash

July 11, 2025

The Federal Circuit recently reversed a PTAB determination on remand that a patent was obvious over applicant admitted prior art (“AAPA”) in combination with prior art patents, holding that expressly designating AAPA as a “basis” for a ground is improper under 35 U.S.C. § 311(b). In doing so, the Court rejected the PTAB’s “blanket rule” that “AAPA used in combination with prior art patents or printed publications under § 311(b) is ipso facto not the basis or part of the basis of a ground.” Ultimately, while the case clarifies that expressly listing AAPA in an IPR ground is improper, the precise line between proper and improper uses of AAPA in other instances remains unclear.

...

Read More

© 2025 Akin Gump Strauss Hauer & Feld LLP. All rights reserved. Attorney advertising. This document is distributed for informational use only; it does not constitute legal advice and should not be used as such. Prior results do not guarantee a similar outcome. Akin is the practicing name of Akin Gump LLP, a New York limited liability partnership authorized and regulated by the Solicitors Regulation Authority under number 267321. A list of the partners is available for inspection at Eighth Floor, Ten Bishops Square, London E1 6EG. For more information about Akin Gump LLP, Akin Gump Strauss Hauer & Feld LLP and other associated entities under which the Akin Gump network operates worldwide, please see our Legal Notices page.