In Praxair Distrib., Inc. v. Mallinckrodt Hospital Prods. IP Ltd., the Federal Circuit found that the printed matter doctrine applies equally to physically embodied information and mental steps, and can be invoked in the patent eligibility context under 35 USC § 101 or the patentability context under 35 USC §§ 102 and 103. Does the court's holding raise another hurdle to patent eligibility, or might the printed mater doctrine provide an avenue for consideration of mental steps in a diagnostic or personalized medicine method claim?

The Patent At Issue

The patent at issue was Mallinckrodt's U.S. Patent 8,846,112, which is listed in the Orange Book for INOMax®, a nitric oxide delivery system indicated for use to improve oxygenation and reduce the need for extracorporeal membrane oxygenation in neonatal patients with hypoxic respiratory failure associated with clinical or echocardiographic evidence of pulmonary hypertension.

The court cited claim 1 as illustrative:

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 preexisting 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.

In the inter partes review proceeding on appeal, the PTAB invalidated all but claim 9 as obvious. Claim 9 depends from independent claim 7 which is similar to claim 1 but recites:

7. 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 pre-existing left ventricular dysfunction; and
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,
(ii) information that patients who have pre-existing left ventricular dysfunction and are treated with inhaled nitric oxide may experience pulmonary edema, and
(iii) a recommendation that, if pulmonary edema occurs in a patient who has pre-existing left ventricular dysfunction and is treated with inhaled nitric oxide, the treatment with inhaled nitric oxide should be discontinued.

Claim 9 recites:

The method of claim 7, further comprising:
performing at least one diagnostic process to identify a neonatal patient who has hypoxic respiratory failure and is a candidate for inhaled nitric oxide treatment;
determining prior to treatment with inhaled nitric oxide that the neonatal patient has pre-existing left ventricular dysfunction;
treating the neonatal patient with 20 ppm inhaled nitric oxide, whereupon the neonatal patient experiences pulmonary edema; and
in accordance with the recommendation of (iii), discontinuing the treatment with inhaled nitric oxide due to the neonatal patient's pulmonary edema.

As discussed in this article, the U.S. District Court for the District of Delaware invalidated this and related patents under 35 USC § 101. The appeal of that decision is still pending.

The Printed Matter Doctrine

The Federal Circuit decision was authored by Judge Lourie and joined by Chief Judge Prost. Judge Newman wrote a concurring opinion agreeing with the ultimate determination of obviousness, but disagreeing with the majority's application of the printed matter doctrine to non-printed matter.

The majority opinion summarizes the printed matter doctrine as follows:

Claim limitations directed to printed matter are not entitled to patentable weight unless the printed matter is functionally related to the substrate on which the printed matter is applied.

According to the majority, "While early cases developing this doctrine applied it to claims literally encompassing 'printed' materials .... we have held that a claim limitation is directed to printed matter if it claims the content of information."

While the PTAB had applied the printed matter doctrine in the context of § 103 (e.g., it did not give weight to the "providing information" limitations in its obviousness analysis), the majority opines that the doctrine is rooted in patent eligibility:

Claim limitations directed to the content of information and lacking a requisite functional relationship are not entitled to patentable weight because such information is not patent eligible subject matter under 35 U.S.C. § 101.

On the other hand, the majority rejected Mallinckrodt's argument that "whether claims are directed to mental steps may only be considered in determining patent eligibility, not obviousness." Instead, the majority found that the printed matter doctrine applies to mental steps:

There is no meaningful distinction between claim limitations directed to written information in Kao, Ngai, and AstraZeneca, verbal information in King, and mentally-processed information here.

The majority explained:

Like the information claimed by printed matter, mental steps or processes are not patent eligible subject matter. .... And while subject matter eligibility underlies the printed matter doctrine ... many of our printed matter cases have arisen in the context of anticipation or obviousness. .... The printed matter doctrine thus raises an issue where the § 101 patent-eligibility inquiry and the § 102 and § 103 novelty and nonobviousness inquiries overlap. .... Because claim limitations directed to mental steps may attempt to capture informational content, they may be considered printed matter lacking patentable weight in an obviousness analysis. Accordingly, 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 Functional Relationship Between Information And Action

Applying the printed matter doctrine to the method claims at issue, the court considered whether the information was "functionally related" to other steps of the claims. The parties, PTAB and Federal Circuit agreed that requirement was met for claim 9:

[C]laim 9 requires a medical provider to take a specific action, discontinuing treatment, as a result of the recommendation limitation. Both parties agree that this suffices to create a functional relationship, and so do we.

Even though the Federal Circuit agreed that this step of claim 9 was entitled to patentable weight, it disagreed with the PTAB finding that the claim as a whole was non-obvious. In particular, where the PTAB had construed the claim as excluding the treatment of LVD patients while the asserted prior art taught treatment of such patients with careful monitoring, the Federal Circuit found that claim 9 does not exclude treatment of such patents, but only requires discontinuing treatment in the event of pulmonary edema.

Eligibility Hurdle Or Helping Hand?

Is the printed matter doctrine another hurdle to patent eligibility, or might it provide a helping hand over other patent eligibility hurdles? Could a mental step that might be disregarded in a Mayo/Alice analysis be given weight under the printed matter doctrine if it is tied to a specific action?

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