. . . In other words, silence is not disclosure and fails to provide sufficient support for a negative claim limitation. . . .
Introduction
In Healthier Choices Management Corp. v. Philip Morris Products S.A., No. 2023-1529 (Fed. Cir. Nov. 22, 2024) (“Decision”), the United States Court of Appeals for the Federal Circuit affirmed the Patent Trial and Appeal Board’s (“PTAB”) invalidation of claims 1–8 of U.S. Patent No. 10,561,170 (“the ’170 patent”) and denial of Healthier Choices Management Corp.’s (“HCMC”) motion to amend by introducing substitute claims. At the heart of the dispute was HCMC’s claims to an electronic pipe, a two-section device designed to combust a material for inhalation by transmitting electric current to a heating element in one section. Central to the case was whether the airflow path within the pipe, specifically its confinement to the second section of the pipe, was adequately disclosed in the patent's specification.
After the PTAB found HCMC’s original claims invalid due to prior art, HCMC attempted to amend the claims to overcome the prior art. However, the proposed amendments, which introduced strict limitations to the airflow path to avoid the prior art, were rejected for lack of written description support. HCMC appealed both the PTAB’s anticipation finding and the denial of its motion to amend to the Federal Circuit.
Background
HCMC’s ’170 patent discloses an electronic pipe comprising two distinct sections: a first pipe section housing the electronic components, such as the battery and printed circuit board, and a second pipe section containing a combustible material reservoir and heating element. During use, electric current flows from the battery to the heating element, combusting material for inhalation. Airflow plays a crucial role in the device’s operation, with the patent describing an “ambient air inlet” that channels air into the pipe to facilitate combustion. However, the specification does not limit the location of the air inlet to a single pipe section, instead describing multiple possible configurations of the air flow within the pipe assembly.
Federal Circuit’s Analysis
Anticipation Under 35 U.S.C. § 102
Philip Morris challenged claims 1–8 of the ’170 patent in two IPR petitions, asserting that the claims were anticipated under 35 U.S.C. § 102 by U.S. Patent Application Publication No. 2012/0160251 (“Hammel”). Hammel disclosed an electronic smoking device with similar components, including a heating element fixed within a combustible material reservoir.
Under § 102, a patent claim is invalid if a single prior art reference discloses every limitation of the claimed invention. See Allergan, Inc. v. Apotex Inc., 754 F.3d 952, 958 (Fed. Cir. 2014). The court reviewed the PTAB’s factual findings for substantial evidence, which requires that a reasonable mind might accept the evidence as adequate to support the conclusion. See Regents of the Univ. of Minn. v. Gilead Scis., Inc., 61 F.4th 1350, 1355 (Fed. Cir. 2023).
HCMC contended that Hammel did not disclose a “heating element fixed in the combustible material reservoir,” a key limitation of the claims. However, expert testimony from Dr. Seetharama Deevi, presented by Philip Morris, demonstrated that Hammel’s device included a heating element fixed within a reservoir, fulfilling this claim limitation. The Federal Circuit found that the PTAB was within its discretion to credit Dr. Deevi’s analysis and that substantial evidence supported the PTAB’s finding of anticipation. Decision at 7. The PTAB thus agreed with Philip Morris, finding that Hammel disclosed every limitation of the challenged claims, including the contested heating element feature.
With the original claims invalidated, HCMC’s only recourse was to amend the claims to overcome the prior art.
Written Description Requirement Under 35 U.S.C. § 112
In response to the PTAB’s invalidation of the original claims, HCMC sought to amend its claims by proposing substitute claims 9–16. The substitute claims introduced a key distinguishing limitation—the “ambient air inlet” was redefined to exclude air passage through the first pipe section, confining airflow to the second section where the heating element and combustible material were located. HCMC argued that this exclusionary limitation overcame the prior art while remaining true to the invention’s disclosure in the specification. The PTAB denied HCMC’s motion to amend, finding that the exclusionary limitation in the proposed claims—that the “ambient air inlet” excluded air passage through the first pipe section—was not adequately supported by the ’170 patent’s specification.
Under 35 U.S.C. § 316(d), a patent owner may cancel challenged claims and propose a reasonable number of substitute claims. See Uniloc 2017 LLC v. Hulu, LLC, 966 F.3d 1295, 1298 (Fed. Cir. 2020). However, these substitute claims must meet all statutory and regulatory requirements, including the written description requirement under 35 U.S.C. § 112. See Aqua Prods. Inc. v. Matal, 872 F.3d 1290, 1314 (Fed. Cir. 2017) (en banc). To satisfy this requirement, the patent’s original specification must reasonably convey to those skilled in the art that the inventor had possession of the amended claims’ subject matter at the time of filing. See Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc). In the context of substitute claims, this means that the specification must explicitly or implicitly support any newly introduced limitations.
Exclusionary or “negative” limitations, such as confinement of airflow to the second pipe section, require clear disclosure in the specification or a necessary implication of the limitation from its context. In its analysis, the Federal Circuit emphasized that “[w]hen the ‘specification is itself silent regarding a negative limitation, testimony from a skilled artisan as to possibilities or probabilities that the recited element would be excluded [does] not suffice.’” Decision at 9 (quoting Novartis Pharmaceuticals Corp. v. Accord Healthcare, Inc., 38 F.4th 1013, 1017 (Fed. Cir. 2022)). In other words, silence is not disclosure and fails to provide sufficient support for a negative claim limitation.
Although the ’170 patent’s specification described an “ambient air inlet” as a small hole or aperture in the second pipe section, it did not affirmatively state that air passage through the first pipe section was excluded. Instead, the specification explicitly disclosed that an air inlet could be placed in other locations, such as the external wall of the casing leading into the first chamber, thereby suggesting that airflow through the first pipe section was not necessarily excluded. Specifically, the description of Figure 4 noted: “an air inlet (not shown), in the form of a hole or aperture, may be located in the external wall of the casing . . . allowing passage of ambient air into the first chamber.” Decision at 9 (emphasis added). This evidence therefore directly contradicted the proposed negative limitation.
From these disclosures, the court found no basis to infer that excluding air passage through the first pipe section was either necessary or inherent to the disclosed invention. By including descriptions of multiple possible airflow configurations, the specification failed to provide the clear exclusion required to support the proposed negative limitation. Without explicit or necessarily implied support, the court concluded that the proposed amendment exceeded the bounds of what was disclosed in the patent's specification.
Conclusion
The Federal Circuit’s decision in Healthier Choices illustrates the difficulties faced by patentees when claims are invalidated during an IPR. Although a patentee may amend and substitute the invalidated claims, any amendment introducing new limitations, particularly negative limitations, must be supported by the original disclosure. This decision highlights the futility of introducing negative or exclusionary claim limitations where the specification fails to affirmatively or necessarily exclude a feature in a manner that conveys possession of the claimed invention to a skilled artisan.
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