In Praxair Distribution, Inc. v. Mallinckrodt Hospital Products IP Ltd., 890 F.3d 1024 (Fed. Cir. 2018), the Federal Circuit affirmed the PTAB's application of the rarely relied on "printed matter doctrine" to conclude that claims directed to a method for providing to a medical provider nitric oxide gas ("NO") along with "information" concerning i) a recommended dose of inhaled NO for treatment of neonates with hypoxic respiratory failure, and ii) that a certain patient class was at risk of pulmonary edema if treated with NO, were unpatentable as obvious.

Claim 1 of U.S. Patent No. 8,846,112 reads as follows:

  1. A method of providing pharmaceutically acceptable nitric oxide gas, the method comprising:

obtaining a cylinder containing compressed nitric oxide gas in the form of a gaseous blend of nitric oxide and nitrogen;

supplying the cylinder containing compressed nitric oxide gas to a medical provider responsible for treating neonates who have hypoxic respiratory failure, including some who do not have left ventricular dysfunction;

providing to the medical provider (i) information that a recommended dose of inhaled nitric oxide gas for treatment of neonates with hypoxic respiratory failure is 20 ppm nitric oxide

and (ii) information that, in patients with pre-existing left ventricular dysfunction, inhaled nitric oxide may increase pulmonary capillary wedge pressure (PCWP), leading to pulmonary edema, the information of (ii) being sufficient to cause a medical provider considering inhaled nitric oxide treatment for a plurality of neonatal patients who (a) are suffering from a condition for which inhaled nitric oxide is indicated, and (b) have pre-existing left ventricular dysfunction, to elect to avoid treating one or more of the plurality of patients with inhaled nitric oxide in order to avoid putting the one or more patients at risk of pulmonary edema. U.S. Patent No. 8,846,112 (issued Sept. 30, 2014).

Praxair filed a petition for inter partes review of all claims based on obviousness. In granting the petition and instituting review, the PTAB stated that, as a matter of claim construction, the "providing information" limitations in the claim are properly considered "printed matter" that are accorded "no patentable weight" because they lacked a functional relationship to the other claim limitations. The Board then disregarded these limitations in its obviousness analysis, and found all but dependent claim 9 unpatentable as obvious.

The printed matter doctrine originated in the 19th century in response to patents directed to business forms, and serves to preclude printed materials from patent-eligible subject matter under Section 101. At issue in the Praxaircase was whether and how the doctrine applies to claims that are not literally directed to printed materials, but incorporate limitations directed to informational content. The majority held that it is proper as a matter of claim construction to parse claim limitations directed to "the content of information," and analyze them under the printed matter doctrine. Only if the printed matter is "functionally related" to its "substrate" is the limitation accorded patentable weight. Praxair, 890 F.3d at 1032-33. In the case of claims not specifically directed to printed matter, the "substrate" requirement has been interpreted by the Federal Circuit as requiring a functional relationship to other claim elements. Id. at 1033.

Mallinckrodt argued that the PTAB improperly applied the printed matter doctrine during claim construction rather than in connection with patentability. However, the panel majority (Judges Lourie and Prost) held that it was proper for the PTAB to do so, and affirmed the PTAB's determination of obviousness of independent claim 1. The majority found that the "providing information" limitation was not functionally related to the other claim limitations, and thus it was proper for the Board not to accord the limitation any patentable weight in its obviousness analysis. Id. at 1032-34.

Also of interest is the majority's treatment of i) dependent claim 3, which added the steps of determining that a neonatal patient has a certain preexisting condition, and "evaluating" the potential benefit of the treatment against the risk that the treatment could lead to pulmonary edema; and ii) dependent claim 7, which concludes with a "recommendation" to discontinue the treatment if pulmonary edema occurs in a patient with the preexisting condition. Id. at 1033-34. Here the Board determined, again as a matter of claim construction, that the "evaluating" and "recommendation" limitations were directed to mental steps that also are not entitled to patentable weight. Id.

The majority rejected Mallinckrodt's argument that whether claim limitations are directed to mental steps may only be considered in the context of determining patent eligibility, and found that these limitations were also directed to printed matter: "[A] limitation that merely claims information by incorporating that information into a mental step will receive patentable weight only if the limitation is functionally related to the substrate. . .[A]dding an ineligible mental process to ineligible information still leaves the claim limitation directed to printed matter." Id.at 1033. The majority further concluded that these additional limitations were similarly not functionally related to the rest of the claims and affirmed the PTAB's conclusion of obviousness. Id.at 1035.

The final printed matter issue addressed by the court concerned dependent claim 9, which depended from claim 7 and added the step of "discontinuing" the treatment with inhaled NO "in accordance with the recommendation of [claim 7]." Because the claim requires a medical provider to take specific action as a result of the recommendation limitation, consistent with the PTAB, the majority found a sufficient functional relationship between the printed matter and other claim limitations, and thus accorded the printed matter in claim 9 patentable weight. Id.at 1036. Nevertheless, the majority reversed the PTAB's determination that this claim was not obvious based on the prior art raised on the petition. Id.at 1036-37.

In her concurring opinion, Judge Newman disagreed that the printed matter doctrine applied to the claims at issue, but concurred in the conclusion as to the obviousness of all the claims addressed on appeal. Judge Newman advocated a bright-line rule that the printed matter doctrine "does not apply to unprinted matter," and that the claimed invention should be analyzed according to the "traditional grounds of sections 102, 103, and 112," rather than "as a newly created category within section 101." Id. at 1038. She took issue with the majority's view that "informational content" could be excised from the claims for the purpose of assessing the novelty and non-obviousness of the claimed invention. In her view, "if the 'informational content' is novel and non-obvious, it may well constitute patentable subject matter." Id. at 1040. Judge Newman also lamented the additional "uncertainty of patent eligibility" that results from what she sees as the majority's "creation of a new printed matter doctrine" that extends to unprinted information and mental steps. Id. at 1039.

In sum, practitioners should be wary of this arguable expansion of the printed matter doctrine both in drafting patent claims and litigating patent claims with informational content.

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