On August 27, 2019, in INO Therapeutics LLC v. Praxair Distribution Inc., in a 2-1 decision, the Federal Circuit upheld a district court decision that method-of-treatment claims, comprising excluding certain patients from treatment, were invalid under 35 U.S.C. § 101.

Claim 1 of U.S. Patent No. 8,795,741 is representative:

1. A method of treating patients who are candidates for inhaled nitric oxide [“iNO”] treatment…comprising:

(a) identifying a plurality of term or near-term neonatal patients who have hypoxic respiratory failure and are candidates for 20 ppm inhaled nitric oxide treatment;

(b) determining that a first patient of the plurality does not have left ventricular dysfunction [“LVD”];

(c) determining that a second patient of the plurality has left ventricular dysfunction, so is at particular risk of increased PCWP leading to pulmonary edema upon treatment with inhaled nitric oxide;

(d) administering 20 ppm inhaled nitric oxide treatment to the first patient; and

(e) excluding the second patient from treatment with inhaled nitric oxide, based on the determination that the second patient has left ventricular dysfunction, so is at particular risk of increased PCWP leading to pulmonary edema upon treatment with inhaled nitric oxide.

The majority of the Federal Circuit panel noted that “[i]t is undisputed that treatment of infants experiencing hypoxic respiratory failure with iNO gas has existed for decades” (slip op. at page 8). The majority acknowledged that “[t]he inventors observed an adverse event [pulmonary edema] that iNO gas causes for certain patients” (Id. at pages 8-9).

The majority focused on step (e) of the claim, reciting the exclusion of such patients from treatment with iNO. The majority characterized this step as “simply an instruction not to act” (Id. at page 10). The majority stated that “[i]n effect, the claim is directed to detecting the presence of LVD in a patient and then doing nothing but leaving the natural processes taking place in the body alone for the group of LVD patients. Accordingly, the claim is directed to the natural phenomenon” (Id.).

The majority distinguished the claims in INO from method-of-treatment claims recently found to be patent-eligible in Vanda Pharmaceuticals Inc. v. West-Ward Pharmaceuticals International Ltd., 887 F.3d 1117 (Fed. Cir. 2018). The majority in INO noted that in Vanda,

[a]fter the risk of QT prolongation was identified for certain metabolizers, the claims did not simply instruct doctors to stop treating those patients with iloperidone based on that information. Instead, the claims leveraged the natural phenomenon to improve treatment for schizophrenia. The claims required the doctor to treat a patient with a specific low-dose range if she had a “poor metabolizer genotype” or a specific high-dose range if she did not have the genotype. (slip op. at page 12).

In contrast, the majority noted that in INO, “the invention is not focused on changing the physiological state of the patient to treat the disease. The claimed invention is focused on screening for a natural law” (Id. at pages 14-15). “Claim 1 does not recite a set of dosages that offer some relief to LVD infants while minimizing the risk of an adverse event. It simply sets out an observation of the adverse event, and then instructs the physician to withhold iNO treatment” (Id. at pages 15-16).

Interestingly, the majority acknowledged that step (d) of claim 1 positively recites administering iNO to a patient who does not have LVD. That is, step (d) requires administering iNO to a certain patient, as opposed to step (e)’s withholding of iNO treatment from a different patient (to let nature take its course). However, the majority found that step (d) “is plainly not the focus of the claimed invention. [Plaintiff-Appellant] concedes this step is not innovative” (Id. at page 11). This is similar to the district court’s analysis, which found that steps (a), (b), (c) and (d) of claim 1 were “routine and conventional in the art” and therefore unable to “transform a patient’s natural risk of developing pulmonary edema, given preexisting LVD and treatment with iNO, into a patentable invention.”

Thus, the majority of the Federal Circuit panel continued the trend, from most cases in the Mayo/Alice line, of considering “inventiveness” in the § 101 inquiry, rather than leaving inventiveness for an inquiry under § 103.

The majority expressed caution about the breadth of its holding, in particular about concerns that the holding could harm the nascent field of personalized medicine. The majority explained that “[w]hile § 101 precludes bare monopolies on natural phenomena, new and inventive methods of treatment in personalized medicine remain patent eligible. We conclude that the specific claims here are ineligible. But we emphasize the narrowness of our holding today, which is limited to the particular claims at issue and is driven by the particular circumstances here” (slip op. at page 22).

Judge Newman dissented from the majority’s opinion on patent-eligibility under § 101. She explained that “[t]he claims are for a method of medical treatment—a class of subject matter whose eligibility under section 101 is established by precedent” (slip op. at page 1). She criticized the majority’s opinion for “not acknowledg[ing] that the claimed multi-step method of treatment of hypoxic respiratory failure does not occur in nature. The majority improperly separates the claims into old and new steps, describes some claim steps as a ‘natural phenomenon’ and some steps as ‘well-understood, routine, and conventional steps,’ and avoids the requirement that a claimed invention is considered as a whole” (Id. at page 2).

Judge Newman acknowledged that the claimed “method of treatment may or may not pass the tests of sections 102 or 103” (Id. at page 2). However, she expressed concern that the majority’s opinion “adds to the inconsistency and unpredictability of this area of patent-supported innovation” (Id. at page 3).

The majority’s opinion in INO suggests that method-of-treatment claims are not per se eligible under § 101. That is, method-of-treatment claims still can face scrutiny under § 101 as being “directed to” natural phenomena, especially when certain method steps are considered to be “routine and conventional in the art.” This contrasts with the clarity some hoped for after the decision in Vanda. As is usually the case with patent claims, the devil is in the details.