Skip to content

PTAB decision invalidating claims as inherently anticipated upheld by Federal Circuit

Procedural History

Arbutus Biopharma Corp. v. Modernatx, Inc. is an appeal from a final written decision in an inter partes proceeding of the Patent Trial and Appeal Board (“PTAB”) that found claims 1-22 of U.S. Patent No. 9,404,127 (“’127 Patent”) invalid as anticipated by prior art. The Federal Circuit affirmed.


Arbutus Biopharma Corporation (“Arbutus”) owns the ’127 Patent, which is directed to an invention that provides stable nucleic acid lipid particles (“SNALP”) and methods of delivering the SNALP.  (Slip Op. at 2.)  SNALP has two morphologies, lamellar or non-lamellar, which describe the physical structure of the particles. Id. The Court noted that the physical property or morphology of the lipid particles depends on two factors: (1) the lipids used for making the formulations and (2) the process used to form the lipid particles. (Slip Op. at 3.) The ’127 Patent identifies five formulations of various compositions, two of which are most relevant to the case, which can be prepared by either Stepwise Dilution Method (“SDM”) or Direct Dilution Method (“DDM”). Id. The ’127 Patent incorporates by reference two patent applications that describe DDM and the apparatuses for carrying out DDM, as well as SDM and the apparatuses for carrying out SDM. (Slip Op. at 4.)
Appellee Moderna Therapeutics (“Moderna”) filed a petition for inter partes review (“IPR”) challenging claims 1-22 of the ’127 Patent, arguing that U.S. Patent No. 8,058,069 (“’069 Patent”) anticipated every claim of the ’127 Patent. Id. The PTAB issued a final written decision finding that all 22 claims were anticipated by the ’069 Patent, which was undisputed prior art, as well as various publications which were incorporated by reference in the ’069 Patent.1 (Slip Op. at 5-7.)
Central to the dispute before the Board was whether element claim 1(d) of the ’127 Patent, which recites a morphology limitation, is inherently disclosed in the ’069 Patent. (Slip Op. at 6.) Moderna contended that the morphology limitation is an inherent natural property resulting from the lipid composition of the formulation and formation process. Id. Arbutus argued that there was no presumption of inherency and that there was no evidence that the ’069 Patent and its formulations would necessarily have the same morphology as disclosed by the ’127 Patent. Id.
The PTAB found independent claim 1 of the ’127 Patent to be inherently anticipated as the morphology limitation is an inherent property or natural result of the disclosures. (Slip Op. at 6-7.)  The PTAB also found that the remaining claims of the ’127 Patent to be invalid as anticipated as well. (Slip Op. at 7.)


The Federal Circuit affirmed the PTAB’s final written decision, focusing on whether the morphology limitation of claim 1 of the ’127 Patent was inherently anticipated by the disclosure of the ’069 Patent and its incorporated references. (Slip Op. at 9.)
After concluding that the ’069 Patent did not explicitly teach the morphology limitation, the Court turned to its analysis of inherent anticipation, upholding the PTAB’s conclusion as supported by substantial evidence. Id. First, the Court looked at the disclosures of the formulations and found that the ’127 and ’069 Patents “disclose the same formulation with ‘almost identical wording’ . . . [and that] [t]he specificity of the disclosures in the ’069 patent is the same as in the ’127 patent.”(Slip Op. at 9-10). Next, the Court evaluated the disclosures of the processes and concluded that the ’127 Patent and the ’069 Patent disclose and describe the process parameter, DDM, in the same way, noting that both patents incorporate the same prior art by reference. (Slip Op. at 10-11.) Finally, because the prior art teaches the same formulations and the same DDM as the ’127 Patent, and because a skilled artisan would only have to follow a “limited number of tools” (five formulations and two processes), the Federal Circuit affirmed the PTAB’s finding that the ’069 Patent inherently anticipates the morphology limitation. (Slip Op. at 11-12.) Since following these disclosures would naturally result in a composition with the inherent morphological property, the Court was “not persuaded that this is a case where there is only a probability that the Morphology Limitation would result . . . .” (Slip Op. at 12.) Therefore, the Court held that “[t]he Board did not err in its determination that the Morphology Limitation of claim 1 is inherently anticipated by the ’069 patent in that its determination is supported by substantial evidence.” Id
The Federal Circuit also upheld the PTAB’s finding that dependent claims 3 and 8-12 of the ’127 Patent were anticipated by the prior art. (Slip Op. at 13-15.) First, the Court found that the ’069 Patent explicitly discloses that the nucleic acid can be mRNA (claim 3 of the ’127 Patent) and that the nucleic acid may be fully encapsulated within the lipid portion of the particle (claim 8 of the ’127 Patent). Second, the Court found that claim 9 of the ’127 Patent, which recites an inverse hexagonal or cubic phase structure as an additional limitation to claim 1, is an inherent property of the non-lamellar morphology limitation that is inherently anticipated in claim 1 and is disclosed by the ’069 Patent through an incorporated reference. (Slip Op. at 13-14.) Third, the Court found claims 10-12 of the ’127 Patent, which recite percentage ranges for a lipid component of claim 1, are anticipated by the prior art because “the ’069 patent and its incorporated references describe nucleic acid-lipid particles and disclose these amounts as an inherent property of the formulations.” (Slip Op. at 14-15.)

Key Takeaways

  1. Patent holders should pay close attention to references that are incorporated into a patent’s written description, as they can be used by a challenger to successfully argue for inherent anticipation.
  2. Where the prior art discloses a limited number of controlling process or formulations, a patent holder should consider and be sensitive to potential inherency arguments.


1 “Together, the ’069 patent and its incorporated references detail several of the same disclosures and experiments as the ’127 patent. The specificity of the disclosure in the prior art is the same as in the ’127 patent.” (Slip Op. at 6.)