In Praxair Distrib. v. Mallinckrodt Hosp. Pdts., (Fed. Circ. May 16, 2018), the Federal Circuit affirmed the PTAB’s application of the printed matter doctrine in an IPR, and determined that all challenged claims were obvious.

Mallinckrodt’s patent is directed to methods of treating newborns having low blood oxygenation with nitric oxide (NO) gas, “to dilate blood vessels in the lungs and … thereby improve blood oxygenation.” Generally, the claims recite methods of providing medical providers with NO gas, and information relating to treatment with NO.

Printed Matter Doctrine

The concept of “printed matter” generally comprises informational content in claims, whether literally “printed” or not. Printed matter is not patent eligible subject matter under 35 U.S.C. § 101, but the printed matter doctrine is often applied in the context of anticipation and obviousness analyses under 35 U.S.C. §§ 102 and 103. If a limitation is directed to printed matter, the printed matter is not given patentable weight unless the printed matter is functionally related to the substrate on which it is applied.

Mallinckrodt argued with respect to claims 1-8 and 10 that the Board erred by applying the printed matter doctrine during claim construction, by extending the printed matter doctrine to include mental steps, by construing the preamble of the claim, and by discounting evidence of secondary considerations.

The court agreed with Praxair that the PTAB “properly addressed the printed matter doctrine during claim construction” because the PTAB’s analysis only required the analysis and interpretation of claim language—ultimately a legal inquiry. The court concluded that the PTAB did not err in declining to read the preamble phrase “pharmaceutically acceptable” as only referring to the physical condition of the gas, and not the informational content that accompanied it. The court also noted that even if the preamble could be read to recite providing such prescribing information, such a preamble would not otherwise have sufficed to create a “functional relationship” between that information and the methods claimed for providing and administering the drug. The court observed that the claims did not recite adjusting treatment according to such information. The claims called merely for providing such information or linked such information to the performance of a purely mental step. The court noted that, “mental steps or processes are not patent eligible subject matter.” Finally, the court held that the Board did not err in discounting evidence of secondary considerations advanced by Mallinckrodt related to the printed matter limitations. “Such printed matter”, wrote the court, “cannot be brought within the ambit of patent eligibility by showing that it was surprising.” “No patentable weight means no patentable weight,” declared the court.

In contrast to its analysis of claims 1-8 and 10, the Board held that a functional relationship did exist in claim 9. Claim 9 required “a medical provider to take a specific action,” discontinuing treatment as a result of information provided to the medical provider. Because the specific action was “based on” the information provided, the court found a functional relationship between the information provided (a recommendation that the medical provider discontinue treatment with inhaled NO) and the step of discontinuing treatment. The court stated that, “we agree with Mallinckrodt that the Board did not err in concluding that the printed matter in claim 9 has a functional relationship to the rest of the claim and giving the printed matter patentable weight.”

However, even after giving patentable weight to the printed matter, the court “must still consider whether claim 9 as a whole would have been obvious.” Based on a separate error in claim construction, the court concluded that the Board erred in its analysis of obviousness, and reversed the Board’s decision that claim 9 was not unpatentable.

Concurring Opinion

Circuit Judge Newman concurred in the judgment but disagreed with the court’s extension of the printed matter doctrine to include information and mental steps. “Mental steps are mental, not printed. The printed matter doctrine is directed to printed matter, not information and not mental steps.” The concurrence agreed that the claims were “invalid based on an obviousness analysis in accord with the law of obviousness,” but cautioned that the use of the printed matter doctrine “converts the patentability analysis into eligibility under section 101.” “It is improper to pluck limitations out of the claims, as of ‘no patentable weight,’ and then to review patentability of the remainder.” The concurrence also notes that “Praxair’s petition for inter partes review was on the ground of obviousness, not printed matter.”


The Praxair decision demonstrates that the printed matter doctrine should be considered in drafting and construing claims, and practitioners should keep in mind that limitations directed to printed matter are not likely to be given patentable weight.