Ino Therapeutics LLC v. Praxair Distribution Inc.

NOTE: This disposition is nonprecedential.

United States Court of Appeals
for the Federal Circuit
______________________

INO THERAPEUTICS LLC, MALLINCKRODT
HOSPITAL PRODUCTS INC., MALLINCKRODT
HOSPITAL PRODUCTS IP LTD.,
Plaintiffs-Appellants

v.

PRAXAIR DISTRIBUTION INC., PRAXAIR INC.,
Defendants-Appellees
______________________

2018-1019
______________________

Appeal from the United States District Court for the
District of Delaware in No. 1:15-cv-00170-GMS, Judge
Gregory M. Sleet.
______________________

Decided: August 27, 2019
______________________

SETH P. WAXMAN, Wilmer Cutler Pickering Hale and
Dorr LLP, Washington, DC, argued for plaintiffs-appel-
lants. Also represented by CLAIRE HYUNGYO CHUNG,
THOMAS SAUNDERS, DAVID P. YIN.

WILLIAM R. PETERSON, Morgan, Lewis & Bockius LLP,
Houston, TX, argued for defendants-appellees. Also repre-
sented by MICHAEL J. ABERNATHY, MARIA DOUKAS, SANJAY
2 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

K. MURTHY, JASON C. WHITE, Chicago, IL; JULIE S.
GOLDEMBERG, Philadelphia, PA.
______________________

Before PROST, Chief Judge, NEWMAN and DYK,
Circuit Judges.
Opinion for the court filed by Chief Judge PROST.
Opinion concurring in part and dissenting in part filed by
Circuit Judge NEWMAN.
PROST, Chief Judge.
INO Therapeutics LLC, Mallinckrodt Hospital Prod-
ucts Inc., and Mallinckrodt Hospital Products IP Ltd. (col-
lectively, “Mallinckrodt”) sued Praxair Distribution Inc.
and Praxair Inc. (collectively, “Praxair”) for patent in-
fringement. Mallinckrodt asserted five patents related to
methods of administering inhaled nitric oxide, including
U.S. Patent Nos. 8,282,966 (“the ’966 patent”), 8,293,284
(“the ’284 patent”), 8,795,741 (“the ’741 patent”), 8,431,163
(“the ’163 patent”), and 8,846,112 (“the ’112 patent”) (col-
lectively, “heart failure patents” or “HF patents”).
Mallinckrodt also asserted five patents related to devices
and methods for administering gas, including U.S. Patent
Nos. 8,573,209 (“the ’209 patent”), 8,776,794 (“the ’794 pa-
tent”), 8,776,795 (“the ’795 patent”), 9,265,911 (“the ’911
patent”), and 9,295,802 (“the ’802 patent”) (collectively,
“delivery system infrared patents” or “DSIR patents”). Af-
ter a bench trial, the United States District Court for the
District of Delaware held all claims of the HF patents inel-
igible and all claims of the DSIR patents not infringed. For
the reasons below, we affirm-in-part, vacate-in-part, and
remand.
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 3

BACKGROUND
I
Inhaled nitric oxide (“iNO”) is a gas that is well known
in the prior art. The U.S. Food and Drug Administration
(“FDA”) approved New Drug Application (“NDA”)
No. N020845 for 100 and 800 ppm nitric oxide for inhala-
tion on December 23, 1999.
Use of iNO gas as a treatment has been “studied and
reported in the literature.” ’741 patent col. 1 ll. 25–26. In
particular, since at least the early 1990s, iNO gas has been
used to treat infants experiencing hypoxic respiratory fail-
ure. According to the Background of the Invention of the
’741 patent, iNO “is an approved drug product for the treat-
ment of term and near-term neonates . . . having hypoxic
respiratory failure associated with clinical or echocardio-
graphic evidence of pulmonary hypertension.” Id. at col.1
ll. 20–24. Hypoxic respiratory failure is “a condition where
oxygen levels in the blood are too low. Nitric oxide func-
tions to dilate blood vessels in the lungs and can thereby
improve blood oxygenation.” Praxair Distribution, Inc. v.
Mallinckrodt Hosp. Prod. IP Ltd., 890 F.3d 1024, 1028
(Fed. Cir. 2018) (citing ’112 patent col. 3 ll. 34–56).
A dose of 20 ppm iNO was also well known in the prior
art for treatment of hypoxic respiratory failure in infants.
J.A. 24–25. For example, one of the asserted patents cites
as prior art U.S. Patent No. 5,485,827 (“Zapol”), which dis-
closes administering 20 ppm iNO treatment. The Zapol pa-
tent issued in 1996.
In 2004, Ikaria Inc. (“Ikaria”) commissioned a study in-
volving iNO gas, referred to as the INOT22 study. The
INOT22 study observed adverse events in certain patients.
Specifically, the study concluded that neonates with a con-
genital heart condition—known as left ventricular dysfunc-
tion (“LVD”)—were at an increased risk of pulmonary
edema when treated with iNO gas. See J.A. 22; ’741 patent
4 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

col. 9 ll. 48-52. According to the ’741 patent specification,
the observation of pulmonary edema among patients in the
INOT22 study was “of interest because pulmonary edema
[had] previously [been] reported with the use of iNO in pa-
tients with LVD, and may be related to . . . overfilling of
the left atrium.” ’741 patent col. 13 ll. 26–29.
The effect of iNO gas on a newborn with LVD is a mat-
ter of human physiology. J.A. 22. For patients with LVD,
the left ventricle cannot sufficiently pump blood out of the
heart. LVD patients depend on the right ventricle to shunt
blood out, a process that requires constriction of the blood
vessels. Administering iNO gas to “neonates or children
with LVD may cause pulmonary edema because iNO
causes the pulmonary vessels to relax.” J.A. 22 (citing Trial
Tr. 1201:5–11). Relaxation of those vessels leads to in-
creased pulmonary blood flow, which causes increased pul-
monary capillary wedge pressure (“PCWP”), which in turn
may lead to pulmonary edema. 1 Id. (citing Trial Tr.
1201:12–17, 1203:9–16).
Beginning in 2009, Ikaria’s subsidiary, INO Therapeu-
tics, began pursuing patents based on this observation.
Eventually, it obtained the five HF patents, which share a
common specification. Claim 1 of the ’741 patent is repre-
sentative. Claim 1 recites:
1. A method of treating patients who are candi-
dates for inhaled nitric oxide treatment, which
method reduces the risk that inhalation of nitric
oxide gas will induce an increase in pulmonary ca-
pillary wedge pressure (PCWP) leading to pulmo-
nary edema in neonatal patients with hypoxic
respiratory failure, the method comprising:

1 Pulmonary capillary wedge pressure “provides an
estimate of left atrial pressure.” ’741 patent col. 5 ll. 20–
22.
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 5

(a) identifying a plurality of term or near-term ne-
onatal patients who have hypoxic respiratory fail-
ure 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;
(c) determining that a second patient of the plural-
ity has left ventricular dysfunction, so is at partic-
ular risk of increased PCWP leading to pulmonary
edema upon treatment with inhaled nitric oxide;
(d) administering 20 ppm inhaled nitric oxide treat-
ment to the first patient; and
(e) excluding the second patient from treatment
with inhaled nitric oxide, based on the determina-
tion that the second patient has left ventricular dys-
function, so is at particular risk of increased PCWP
leading to pulmonary edema upon treatment with
inhaled nitric oxide.
’741 patent col. 14 ll. 28–49 (emphases added).
INO Therapeutics also obtained patents related to de-
vices and methods for providing iNO gas to patients via gas
cylinders. These patents, known as the DSIR patents,
share a specification. Claim 1 of the ’794 patent is repre-
sentative of the device claims and reads:
1. A gas delivery device comprising:
a gas source to provide therapy gas comprising ni-
tric oxide;
a valve attachable to the gas source, the valve in-
cluding an inlet and an outlet in fluid communica-
tion and a valve actuator to open or close the valve
to allow the gas through the valve to a control mod-
ule that delivers the therapy gas comprising nitric
6 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

oxide in an amount effective to treat or prevent hy-
poxic respiratory failure; and
a circuit including:
a memory to store gas data comprising one or more
of gas identification, gas expiration date and gas
concentration; and
a processor and a transceiver in communication
with the memory to send and receive signals to
communicate the gas data to the control module
that controls gas delivery to a subject and to verify
one or more of the gas identification, the gas concen-
tration and that the gas is not expired.
Id. at col. 17 ll. 15–32 (emphases added).
II
Ikaria eventually merged with Mallinckrodt Hospital
Products Inc. Mallinckrodt Hospital Products IP Ltd. now
owns approved NDA No. N020845 for nitric oxide.
Mallinckrodt is the exclusive supplier of iNO gas in the
United States, which it sells under the brand name INO-
max®.
Praxair is an industrial gas company seeking to sell ge-
neric iNO gas cylinders. Praxair filed an Abbreviated New
Drug Application (“ANDA”) seeking approval to market
Noxivent, a generic form of 100 and 800 ppm nitric oxide
gas for inhalation. 2 J.A. 8. In addition, Praxair acquired a
company that developed a gas delivery system, called the
NOxBOXi iNO system.
Mallinckrodt sued Praxair in the District of Delaware
in 2015. Mallinckrodt alleged that Praxair’s proposed

2 Praxair filed a letter advising that the FDA ap-
proved its ANDA for Noxivent on October 2, 2018.
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 7

ANDA product, Noxivent, infringed Mallinckrodt’s HF pa-
tents and device claims of the DSIR patents when used
with Mallinckrodt’s DSIR system. Mallinckrodt also al-
leged that Praxair’s proposed NOxBOXi device infringed a
method claim of the DSIR patents.
The case proceeded to a seven-day bench trial. In Sep-
tember 2017, the district court issued a memorandum and
order concluding that the HF patents were ineligible under
§ 101 and the DSIR patents were not infringed. 3 J.A. 1–
45, 46. The district court entered judgment. J.A. 47–48.
Mallinckrodt now appeals. We have jurisdiction under
28 U.S.C. § 1295(a)(1).
DISCUSSION
I
For entry of judgment under Rule 52(c), we review the
district court’s factual findings for clear error and its legal
conclusions de novo. Intellectual Ventures I LLC v. Syman-
tec Corp., 838 F.3d 1307, 1312 (Fed. Cir. 2016) (citing EBC,
Inc. v. Clark Bldg. Sys., Inc., 618 F.3d 253, 273 (3d Cir.
2010)). “Eligibility under 35 U.S.C. § 101 is a question of
law, based on underlying facts.” SAP Am., Inc. v. InvestPic,
LLC, 898 F.3d 1161, 1166 (Fed. Cir. 2018).

3 In a related appeal, this court recently held that
claims 1–11 of the ’112 patent were obvious. Praxair, 890
F.3d 1024. We concluded that: “It is undisputed that dis-
continuing a treatment in response to a serious side effect
was known in the prior art. It is also undisputed that pul-
monary edema is a potentially fatal condition. And [the
prior art] taught that administering ‘[nitric oxide] may lead
to pulmonary edema in patients with LVD.’” Id. at 1037
(alteration in original) (citations omitted) (holding claim 9
was obvious).
8 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

Mallinckrodt’s appeal proceeds in three parts. First,
Mallinckrodt contends that the district court erred by con-
cluding that the asserted claims of the HF patents are in-
eligible under § 101. Second, Mallinckrodt argues that the
district court erroneously construed the term “verify” when
analyzing whether Praxair’s proposed gas cylinder in-
fringes the DSIR patents. Third, Mallinckrodt avers that
the district court improperly entered judgment on certain
unasserted claims. We address each argument in turn.
II
Section 101 provides that “[w]hoever invents or discov-
ers any new and useful process, machine, manufacture, or
composition of matter, or any new and useful improvement
thereof, may obtain a patent therefor, subject to the condi-
tions and requirements of this title.” 35 U.S.C. § 101. How-
ever, § 101 “contains an important implicit exception.
‘[L]aws of nature, natural phenomena, and abstract ideas’
are not patentable.” Mayo Collaborative Servs. v. Prome-
theus Labs., Inc., 566 U.S. 66, 70 (2012) (alteration in orig-
inal) (quoting Diamond v. Diehr, 450 U.S. 175, 185 (1981)).
To analyze whether a claim involves eligible subject
matter, we apply a two-step test. First, we evaluate
whether the claims are “directed to” a patent-ineligible con-
cept, such as a natural phenomenon. Athena Diagnostics,
Inc. v. Mayo Collaborative Servs., LLC, 915 F.3d 743, 749
(Fed. Cir. 2019) (quoting Alice Corp. v. CLS Bank Int’l, 573
U.S. 208, 217 (2014)). If so, we ask whether the limitations
of the claim, considered individually and as an ordered
combination, “‘transform the nature of the claim’ into a pa-
tent-eligible application.” Id. (quoting Mayo, 566 U.S. at
78).
Applying this test, we agree with the district court that
claim 1 of the ’741 patent is ineligible. It is undisputed that
treatment of infants experiencing hypoxic respiratory fail-
ure with iNO gas has existed for decades. The inventors
observed an adverse event that iNO gas causes for certain
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 9

patients. The patent claim does no more than add an in-
struction to withhold iNO treatment from the identified pa-
tients; it does not recite giving any affirmative treatment
for the iNO-excluded group, and so it covers a method in
which, for the iNO-excluded patients, the body’s natural
processes are simply allowed to take place. Consequently,
the claim here is directed to the natural phenomenon. The
claim, apart from the natural phenomenon itself, involves
only well-understood, routine, and conventional steps. For
the reasons below, claim 1 of the ’741 patent fails to recite
eligible subject matter. 4
A
We begin with the first step of the Mayo/Alice test. A
close review of representative claim 1 confirms that the
claim is “directed to” a natural phenomenon.
The natural phenomenon here is undisputed. A neo-
nate patient’s body will react to iNO gas in a certain way
depending on whether or not the patient has a congenital
heart condition called LVD. Namely, if the patient has
LVD, iNO gas can induce a life-threatening event known
as pulmonary edema. As the district court found, Praxair’s
expert, Dr. Lawson, credibly testified that “the ‘standard
observation’ that a dysfunctional ventricle, in combination
with increased blood flow, could cause a backup of venous
blood, and, in turn, edema,” is a phenomenon “taught to
first year medical students.” J.A. 22 (quoting Trial Tr.
1203:17–24). In short, while nitric oxide lessens con-
striction, increases blood flow, and can help normal pa-
tients with hypoxic respiratory failure, it will harm a
patient suffering from LVD and may even result in death.

4 The district court treated claim 1 of the ’741 patent
as representative of the HF patents. J.A. 21. The parties
did not argue the eligibility of the claims separately on ap-
peal.
10 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

Turning to the claim language, claim 1 is “directed to”
that observation about the natural phenomenon. As
drafted, the claim instructs a physician to administer iNO
gas to non-LVD patients as before, while now excluding the
LVD patients. The exclusion step merely restates the nat-
ural law. It expressly recites “excluding the second patient
from treatment with inhaled nitric oxide, based on the de-
termination 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.” ’741 patent col. 14 ll. 45–49.
On appeal, Mallinckrodt characterizes this as “selec-
tive administration.” Appellant’s Br. 3. In Mallinckrodt’s
view, the “exclusion” step is the reason the claims are not
directed to a natural phenomenon as no treatment protocol
had screened for such an adverse event before. Id. at 27.
Ironically, it is this “new” instruction that directs the
claims to the particular natural phenomenon here.
Properly understood, this added step is simply an in-
struction not to act. In effect, the claim is directed to de-
tecting 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.
Indeed, Mallinckrodt cannot dispute that the patented
method does not propose a new way of treating LVD pa-
tients that leverages this discovery (e.g., by titrating the
iNO dose). Instead, the claim simply requires that the pa-
tient not be treated with iNO. This is significant because
a claim not to treat—i.e., not to disturb these naturally-oc-
curring physiological processes within the LVD patient’s
body—risks monopolizing the natural processes them-
selves.
Resisting this conclusion, Mallinckrodt argues that its
claims cover an eligible “method of treatment.” Appellant’s
Br. 33. In Mallinckrodt’s view, the HF patent claims
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 11

cannot be directed to a natural phenomenon because they
recite a treatment step. Specifically, claim 1 requires the
affirmative act of “administering 20 ppm inhaled nitric ox-
ide treatment”—a well-known dosage—to a patient with-
out LVD. ’741 patent col. 14 ll. 43–44. According to
Mallinckrodt, claims drafted to include treatment steps are
automatically patent eligible because they involve an “act,”
and Mayo requires nothing more. We disagree.
Mallinckrodt oversimplifies the Mayo/Alice test and
our subsequent case law. The first step of the Supreme
Court’s test requires us to evaluate whether the claim is
“directed to” a natural phenomenon. This determination
involves a probing inquiry, which demands a careful read-
ing of the claim language in relation to the particular nat-
ural phenomenon in each case. Therefore, in “this first
step, we consider the claims ‘in their entirety to ascertain
whether their character as a whole is directed to excluded
subject matter.’” ChargePoint, Inc. v. SemaConnect, Inc.,
920 F.3d 759, 765 (Fed. Cir. 2019) (quoting Internet Patents
Corp. v. Active Network, Inc., 790 F.3d 1343, 1346 (Fed. Cir.
2015)); see also Athena, 915 F.3d at 750 (“The step one ‘di-
rected to’ inquiry focuses on the claim as a whole.”).
A closer look at the claim language as a whole confirms
that the focus of the invention is not on a new way of actu-
ally treating the underlying condition of hypoxic respira-
tory failure. Nor does it recite a way of reducing the risk of
pulmonary edema while providing some level of treatment
to those patients. Rather, the focus of the invention is
screening for a particular adverse condition that, once
identified, requires iNO treatment be withheld. A treat-
ment step of administering a prior art dosage is also pre-
sent. But that step is plainly not the focus of the claimed
invention. Mallinckrodt concedes this step is not innova-
tive. Mallinckrodt does not point to “any innovation other
than its [purported] discovery of the natural law.” Athena,
915 F.3d at 752.
12 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

Mallinckrodt’s reliance on Vanda Pharmaceuticals Inc.
v. West-Ward Pharmaceuticals International Ltd., 887 F.3d
1117 (Fed. Cir. 2018), is therefore misplaced. In Vanda,
the claims recited an actual improved treatment for schiz-
ophrenia. The inventors discovered a set of natural rela-
tionships between iloperidone, a patient’s CYP2D6
metabolism, and the relative risk of “QTc prolongation.”
Id. at 1135. QT prolongation in patients can lead to “seri-
ous cardiac problems.” Id. at 1121. After 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. In-
stead, the claims leveraged the natural phenomenon to im-
prove 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. Id. at 1135.
By leveraging the natural phenomenon, the specific dosing
protocol treated all such patients while still “lowering the
risk of QTc prolongation.” Id. at 1136.
As a result, the majority concluded that the claims in
Vanda were not “directed to” a natural law under the first
step of the analysis. As a whole, the invented treatment
recited a specific new way to provide a therapeutic benefit
to patients suffering from schizophrenia:
The claims here are directed to a specific method of
treatment for specific patients using a specific com-
pound at specific doses to achieve a specific out-
come. They recite more than the natural
relationship between CYP2D6 metabolizer geno-
type and the risk of QTc prolongation. Instead,
they recite a method of treating patients based on
this relationship that makes iloperidone safer by
lowering the risk of QTc prolongation.
Id. (emphases added).
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 13

Here, the invention does not improve treatment of the
underlying conditions in question—pulmonary edema and
hypoxic respiratory failure—by taking advantage of the
body’s natural processes. The inventors observed a natural
phenomenon about how the body reacts to iNO gas that ap-
pears to be relevant to such diseases: patients with LVD
can be harmed while other patients will not face such
harm. But the claim language stops well short of an im-
proved treatment method. Unlike Vanda, claim 1 does not
recite a specific method of treating the disease using an im-
proved set of specific doses in light of this discovery. In-
stead, the broad directive to exclude all neonatal patients
with LVD from iNO treatment (while continuing to treat
other patients according to the established dose), collapses
into a claim focused on the natural phenomenon.
Our recent decisions following Vanda bolster our con-
clusion. See Nat. Alternatives Int’l, Inc. v. Creative Com-
pounds, LLC, 918 F.3d 1338 (Fed. Cir. 2019); Endo Pharm.
Inc. v. Teva Pharm. USA, Inc., 919 F.3d 1347 (Fed. Cir.
2019). In Natural Alternatives and Endo Pharmaceuticals,
we explained why the specific method claims at issue re-
cited treatments like those in Vanda that utilized the nat-
ural law in a patent-eligible manner. In particular, we
reasoned that the claims were not “directed to” the natural
law itself. Instead of focusing on the information about the
natural law, the invention used the law to produce a
change in the natural state of the patient to treat a condi-
tion.
In Natural Alternatives, the claims related to using di-
etary supplements to increase an athlete’s anaerobic work-
ing capacity. 918 F.3d at 1341. If certain quantities of
beta-alanine are given to a human, “homeostasis is over-
come, and the subject’s body will produce greater levels of
creatine,” which “in turn, results in specific physiological
benefits for athletes engaged in certain intensive exercise.”
Id. at 1344. “The claims not only embody this discovery,
they require . . . actually administer[ing] the dosage form
14 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

claimed in the manner claimed, altering the athlete’s phys-
iology to provide the described benefits.” Id. (emphases
added).
Thus, the focus of the invention in that case was a
“treatment.” The claim used a particular dose of a sub-
stance to obtain a specific “benefit” by “altering the sub-
ject’s natural state.” Id. at 1345.
Likewise, in Endo Pharmaceuticals, we concluded that
the asserted claims were not “directed to” patent-ineligible
subject matter but “a patent-eligible method of using oxy-
morphone or a pharmaceutically acceptable salt thereof to
treat pain in a renally impaired patient.” 919 F.3d at 1353
(emphasis added). That conclusion was supported by the
specification. “The specification predominantly describes
the invention as a method that treats renally impaired pain
patients with less oxymorphone while still treating their
pain. Indeed, the specification explains that the method
‘avoid[s] possible issues in dosing’ and allows for treatment
with ‘the lowest available dose’ for patients with renal im-
pairment.” Id. We reasoned:
In Vanda, the inventors recognized the relation-
ship between iloperidone dosage and the patient’s
CYP2D6 poor metabolizer genotype, but that was
not what they claimed. Similarly, the inventor
here recognized the relationship between oxy-
morphone and patients with renal impairment, but
that is not what he claimed. Rather, he claimed an
application of that relationship—specifically, a
method of treatment including specific steps to ad-
just or lower the oxymorphone dose for patients
with renal impairment.
Id. at 1354 (discussing Vanda, 887 F.3d at 1135).
Here, by contrast, 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
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 15

a natural law. Information about an adverse event was ob-
served by the inventors. The patent instructs doctors to
screen for that information. Once the information is de-
tected, no iNO treatment is given. And as far as the claim
specifies, the patient’s state may remain unchanged and
natural bodily processes may proceed.
Therefore, the claims here are readily distinguishable
from other cases that actually integrate or leverage natural
laws to an eligible method of treatment for a particular dis-
ease. The patent does not delve into the complexities of
dosing to more effectively “treat” different classes of pa-
tients as in Vanda, Natural Alternatives, and Endo Phar-
maceuticals—by leveraging knowledge about a natural
correlation to understand what amounts of a particular
drug prove therapeutic for each patient.
Mallinckrodt’s attempt to liken this case to Rapid Liti-
gation Management Ltd. v. CellzDirect, Inc., 827 F.3d 1042
(Fed. Cir. 2016), is also unsuccessful. The claims in
CellzDirect are distinguishable for at least two reasons.
First, unlike the claims in CellzDirect, the HF patents do
not claim an improved laboratory method. Id. at 1048 (“In-
deed, the claims recite a ‘method of producing a desired
preparation of multi-cryopreserved hepatocytes.’”). Sec-
ond, the pitfall in the district court’s reasoning in CellzDi-
rect is not present here. There, the district court
essentially stopped its analysis after identifying a “natural
law”—the cells’ “capability of surviving multiple freeze-
thaw cycles.” Id. We cautioned that the cells’ ability to
“undergo the process does not make the claim ‘directed to’
that natural ability.” Id. Rather, we examined how the
claims used that purported natural law and concluded the
specific steps used the law to improve the process for actu-
ally “preserving” the “cells for later use.” Id.
Here, a careful reading of the claim language confirms
no such corresponding improvement in “treating” patients
is achieved. Claim 1 does not recite a set of dosages that
16 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

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 with-
hold iNO treatment. 5
In short, after observing an adverse reaction, the in-
ventors could have developed a way to treat the diseases in
question here based on their knowledge about the body’s
ability to undergo the phenomenon. The claimed inven-
tions in Vanda, Natural Alternatives, and Endo Pharma-
ceuticals all did so. But the HF patent claims do not.
Instead, they remain “directed to” the natural phenomenon
itself.
Mallinckrodt’s remaining arguments carry little force.
First, Mallinckrodt takes issue with the district court’s
phraseology. Specifically, it points to a single sentence in
the decision that suggests the first step of Mayo/Alice is
satisfied if the claims “touch upon” the natural law.
J.A. 20. However, Mallinckrodt concedes that a few sen-
tences later, the district court recites and applies the
proper standard. J.A. 21 (“At step one of the Alice two-step
framework, the court asks whether the claims are directed
to patent ineligible subject matter . . . .”).
Next, Mallinckrodt latches onto the Supreme Court’s
statement in Mayo that “a new way of using an existing

5 Mallinckrodt’s reliance on Prometheus Laborato-
ries, Inc. v. Roxane Laboratories, Inc., 805 F.3d 1092 (Fed.
Cir. 2015), is unavailing. In Prometheus, we noted that
“[s]ingling out a particular subset of patients for treatment
. . . may reflect a new and useful invention that is patent
eligible despite the existence of prior art or a prior art pa-
tent disclosing the treatment method to patients gener-
ally.” Id. at 1098. But Prometheus did not concern § 101.
In addition, Mallinckrodt’s claims do not resemble the
method of treatment postulated in Prometheus.
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 17

drug” remains patentable. Appellant’s Br. 40 (quoting
Mayo, 566 U.S. at 87). But Mallinckrodt did not develop a
new use for an old drug that provides a therapeutic benefit.
The claimed method here recites an old use of an old drug.
Then it proposes no use. Per the exclusion step, the iden-
tified patient population is simply not treated with iNO at
all. Mallinckrodt cites no authority for the proposition that
such claims constitute an eligible new “use” as contem-
plated by Mayo and its progeny.
Finally, Mallinckrodt contends that neither the Su-
preme Court nor this court has held that a “new protocol”
is ineligible subject matter. Appellant’s Br. 35. But a pa-
tent draftsman’s decision to pen a claim as a “protocol” does
not exempt those claims from being scrutinized under the
Supreme Court’s controlling two-part test. As with all pa-
tent claims, we must first determine whether the claimed
method is “directed to” a natural phenomenon. Having
done so, we turn to the second step of the analysis.
B
Mallinckrodt contends that the district court erred at
the second step of the Mayo/Alice test by concluding that
the additional limitations do not recite an “inventive con-
cept” that transforms the claims. In response, Praxair ar-
gues that the additional limitations amount to nothing
more than routine and conventional steps and a general in-
struction to apply the natural phenomenon.
Under the second step, we examine the elements of the
claims, individually and as an ordered combination, to de-
termine whether they contain an “inventive concept” suffi-
cient to “transform the claimed naturally occurring
phenomena into a patent-eligible application.” Cleveland
Clinic Found. v. True Health Diagnostics LLC, 859 F.3d
1352, 1361 (Fed. Cir. 2017) (citing Mayo, 566 U.S. at 71–
72). “A claim that recites an abstract idea, law of nature,
or natural phenomenon must include ‘additional features’
to ensure ‘that the [claim] is more than a drafting effort
18 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

designed to monopolize the [abstract idea, law of nature, or
natural phenomenon].’” Ariosa Diagnostics, Inc. v. Se-
quenom, Inc., 788 F.3d 1371, 1377 (Fed. Cir. 2015) (altera-
tions in original) (quoting Mayo, 566 U.S. at 77–78).
“[S]imply appending conventional steps, specified at a high
level of generality” to the claimed law does not make it pa-
tentable. Mayo, 566 U.S. at 82.
Critically, the “inventive concept necessary at step two
of the Mayo/Alice analysis cannot be furnished by the un-
patentable law of nature (or natural phenomenon or ab-
stract idea) itself.” Genetic Techs. Ltd. v. Merial L.L.C., 818
F.3d 1369, 1376 (Fed. Cir. 2016). “That is, under the
Mayo/Alice framework, a claim directed to a newly discov-
ered law of nature (or natural phenomenon or abstract
idea) cannot rely on the novelty of that discovery for the
inventive concept necessary for patent eligibility; instead,
the application must provide something inventive, beyond
mere ‘well-understood, routine, conventional activity.’” Id.
(quoting Mayo, 566 U.S. at 73).
Mallinckrodt does not meaningfully dispute the district
court’s findings that the various steps of claim 1 of the ’741
patent are routine and conventional. Here, “the steps in
the claimed processes (apart from the natural laws them-
selves) involve well-understood, routine, conventional ac-
tivity previously engaged in by researchers in the field.”
Mayo, 566 U.S. at 73.
First, the claim recites the step of “identifying” candi-
dates for treatment with 20 ppm iNO. As the district court
found, “[t]he specification . . . makes it clear that identify-
ing patients who have hypoxic respiratory failure and are
candidates for 20 ppm of iNO treatment is routine and con-
ventional in the art.” J.A. 24 (discussing ’741 patent col. 1
ll. 20–24, 49–50).
We then turn to the two “determining” steps. The
claim instructs a doctor to determine that a first patient
“does not have left ventricular dysfunction” and determine
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 19

that a second patient “has left ventricular dysfunction,
[putting that patient] at particular risk of . . . pulmonary
edema upon treatment with inhaled nitric oxide.” ’741 pa-
tent col. 14 ll. 39–42. Mallinckrodt concedes it did not in-
vent a new way of detecting LVD. Indeed, as the district
court concluded, “the specification explicitly states that
‘[i]dentifying patients with pre-existing LVD is known to
those skilled in the medicinal arts, and such techniques for
example may include assessment of clinical signs and
symptoms of heart failure, or echocardiography diagnostic
screening.’” J.A. 24–25 (quoting ’741 patent col. 5 ll. 15–
19).
The next step—“administering” a dosage of 20 ppm of
iNO gas—is well-known. See J.A. 25 (quoting ’741 patent
col. 14 ll. 43–44). Mallinckrodt does not challenge the dis-
trict court’s finding on this point.
Finally, the last step of claim 1 directs physicians to
“exclud[e]” a patient with LVD from iNO treatment be-
cause of the determination that he is at an increased risk
of pulmonary edema when treated with iNO. ’741 patent
col. 14 ll. 45–49. As discussed above at length, this “do not
treat” step essentially embodies the natural phenomenon
at issue in this case—the insight that nitric oxide will ad-
versely affect a neonate with LVD. “To transform an un-
patentable law of nature into a patent-eligible application
of such a law, one must do more than simply state the law
of nature while adding the words ‘apply it.’” Mayo, 566 U.S.
at 72. This would be quite a different case if the inventors
had invented a new way of titrating the dose. But this
claim, unaccompanied by a recitation of some affirmative
treatment, is directed to the natural law.
In essence, claim 1 boils down to an instruction to doc-
tors: when treating neonatal patients with iNO gas, take
into account their natural reaction to iNO gas. Do not give
iNO gas to patients with LVD; otherwise, proceed with
treatment. Any other steps are either necessary to
20 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

manifest the natural law or are undisputedly routine and
conventional.
As in Mayo, such an instruction, even when viewed as
an ordered combination with other active steps, does not
transform the claims. In Mayo, the Court reasoned that
“[a]nyone who wants to make use of these laws must first
administer a thiopurine drug and measure the resulting
metabolite concentrations, and so the combination
amounts to nothing significantly more than an instruction
to doctors to apply the applicable laws when treating their
patients.” Mayo, 566 U.S. at 79.
The same is true with the natural phenomenon here
that iNO gas causes an adverse reaction in LVD patients.
Anyone who wants to use the natural phenomenon must
first identify “candidates for inhaled nitric oxide gas treat-
ment” and determine whether a given patient has the LVD
heart condition. In turn, the claimed combination of treat-
ing patients without LVD with an existing dosage while ex-
cluding patients with LVD from iNO treatment amounts to
little more than an instruction to doctors to “apply” the ap-
plicable law when treating their patients.
Therefore, whether viewed individually or as an or-
dered combination, the claims here do not recite a patent-
eligible application under the second step of Mayo/Alice.
Even if a newly discovered natural law could somehow
render the claims patent eligible at step two of Mayo/Alice,
that is not the situation here. Although the inventors
claimed to have discovered that administration of iNO to
neonates with LVD “may be detrimental,” the specification
suggests otherwise. ’741 patent col. 9 l. 51. The specifica-
tion explicitly notes that the incidence of pulmonary edema
among patients in the INOT22 study was “of interest be-
cause pulmonary edema [was] previously reported with the
use of iNO in patients with LVD, and may be related
to . . . overfilling of the left atrium.” Id. at col. 13 ll. 26–29.
The district court found the instruction to “exclude”
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 21

patients potentially experiencing an adverse event was
conventional. The court’s finding was based in part on ad-
missions from one of the named inventors. J.A. 26 n.5 (cit-
ing Trial Tr. 641:25–642:4); see also J.A. 26 (“Plaintiffs
cannot seriously contend that it is a new practice to exclude
certain patients from treatment with a drug when those
patients are at an increased risk of experiencing negative
side effects from the drug.”).
Mallinckrodt argues there were benefits to not treating
LVD patients with iNO. According to Mallinckrodt, its
amended protocol resulted in “a 90% reduction in severe
adverse events.” Appellant’s Br. 9. Relatedly, Mallinck-
rodt argues its alleged discovery “upend[ed]” the prior
standard of care as no FDA counterindication existed for
patients with pre-existing LVD. Appellant’s Reply Br. 20.
But these arguments fail. These benefits result solely from
the alleged discovery of the phenomenon itself—not an in-
ventive application of it, and the patent applicant here did
not in fact discover the natural phenomenon.
Mallinckrodt’s argument that its claims do not broadly
preempt treatment of neonates with LVD is a red herring.
Appellant’s Br. 48. As it stands, Mallinckrodt has observed
that use of iNO gas with LVD patients suffering from hy-
poxic respiratory failure leads to adverse events. It has
claimed not treating those patients with the gas. At least
as a practical matter, as far as the record shows, this claim
is broadly preemptive of uses of the natural phenomenon.
Regardless, Mallinckrodt’s attempt to argue that a lack of
total preemption confers eligibility misses the mark.
“Preemption is sufficient to render a claim ineligible under
§ 101, but it is not necessary.” Athena, 915 F.3d at 752
(emphasis added).
Inviting us to ignore the governing inquiry under
Mayo/Alice, Mallinckrodt makes several policy arguments.
Principally, Mallinckrodt argues that the district court’s
decision hampers the emerging field of personalized
22 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

medicine. Appellant’s Br. 50–51. Mallinckrodt’s position
is unpersuasive. While § 101 precludes bare monopolies on
natural phenomena, new and inventive methods of treat-
ment in personalized medicine remain patent eligible. 6 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.
For the reasons above, we affirm the district court’s de-
cision that claim 1 of the ’741 patent is ineligible under
§ 101, as are asserted claims 4, 7, 9, and 18 of the ’741 pa-
tent, claim 20 of the ’966 patent, claim 18 of the ’284 patent,
claims 9, 11, 13, and 15 of the ’163 patent, and claims 1, 7,
and 9 of the ’112 patent.
III
Turning to the DSIR patents, Mallinckrodt takes issue
with the district court’s interpretation of the “verify” term.
Claim 1 of the ’794 patent requires the device “verify one
or more of the gas identification, the gas concentration and
that the gas is not expired.” ’794 patent col. 17 ll. 30–32.
The term “verify” was never formally construed by the
district court. Thus, the district court applied the term’s
plain and ordinary meaning. It found that the system does
not “verify” the gas data when one simply takes a meter
from Mallinckrodt’s gas cylinder (containing data about the
gas from the manufacturer) and uses it with a Praxair gas

6
To be certain, we do not hold that every treatment
that contemplates adverse events—whether known or
newly discovered—will lack claim elements that prove
transformative. But, here, proceeding with the prior art
treatment for hypoxic respiratory failure while offering no
solution for neonatal patients with LVD does not transform
these particular claims.
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 23

cylinder (which does not contain a meter with gas data).
See J.A. 36–39. The district court interpreted the claim
term to require that the gas delivery system verify data
about the actual gas in the “gas source” (i.e., the cylinder
being used). J.A. 37–38. In Mallinckrodt’s view, the DSIR
patent claims are practiced when any iNO cylinder is com-
bined with a circuit storing gas data—even if the data is
unrelated to the particular gas in the cylinder. Mallinck-
rodt’s attempt to undo its loss on infringement by redraw-
ing the metes and bounds of the claim is unavailing.
The plain language of the representative claim con-
firms the district court’s determination was correct. Claim
1 of the ’794 patent recites a “gas delivery device” with “a
gas source” to provide iNO “therapy gas.” ’794 patent
col. 17 ll. 15–16. “A valve” is used to control the gas via a
“control module.” Id. at col. 17 ll. 17–20. Finally, there is
a “circuit,” which includes “a memory” to store “gas data”
about “gas identification, gas expiration date and gas con-
centration.” Id. at col. 17 ll. 23–26. A “processor and a
transceiver” send gas data between the circuit’s memory
and the control module on the valve to “verify one or more
of the gas identification, the gas concentration and that the
gas is not expired.” Id. at col. 17 ll. 27–32 (emphases
added). The “gas” throughout the claim consistently refers
to the specific contents of the “gas source” administered to
the patient. Thus, “gas data” relates to the actual gas in-
side the cylinder.
This conclusion is further confirmed by the specifica-
tion. The fundamental purpose of the invention is to im-
prove patient safety by reducing error during the
administration of iNO gas. As the specification states,
“[t]here is a need for a gas delivery device that integrates a
computerized system to ensure that patient information
contained within the computerized system matches the gas
that is delivered by the gas delivery device.” Id. at col. 1
ll. 40–43.
24 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

Accordingly, the district court’s interpretation of the
plain language of the claims was correct. Mallinckrodt
does not dispute that under the district court’s interpreta-
tion of the plain meaning of the claims, Praxair’s cylinder
does not infringe.
Relatedly, the district court found that because Prax-
air’s delivery system (NOxBOXi) does not “verify” the gas
either, it does not infringe claim 15 of the ’794 patent,
which is representative of the DSIR patents’ method
claims. We agree. Mallinckrodt’s expert, Dr. Schaafsma,
testified that the NOxBOXi’s gas data does not come from
the gas source. J.A. 40–41 (discussing J.A. 1449, 1451).
Instead, Dr. Schaafsma testified that “verification” could
occur when certain data from one circuit board—the Medi-
Board—is compared to data on another circuit—the Single
Board Computer (“SBC”). Id. But as the district court
found, the MediBoard’s data is populated with the value
held by the SBC. Id. Therefore, under Mallinckrodt’s read-
ing, the data is “verified” by comparing the value to itself.
The district court correctly found it difficult “to understand
how comparing a value to itself could satisfy the claim
phrase ‘verify the gas data.’” Id. In light of the intrinsic
evidence above, Mallinckrodt’s position is unsupported.
Therefore, we affirm the district court’s determination of
noninfringement for asserted claims 1 and 15 of the ’794
patent, claim 6 of the ’209 patent, claims 1 and 15 of the
’795 patent, claims 1 and 10 of the ’911 patent, and claims
1 and 10 of the ’802 patent.
IV
Finally, Mallinckrodt challenges a technical error in
the district court’s final judgment order. Specifically, the
district court did not limit its ruling to the asserted claims
before it. Instead, the court erroneously made a blanket
ruling that each Mallinckrodt patent in its entirety was in-
valid or not infringed. J.A. 47. In Praxair’s view, the judg-
ment was justified. But Praxair offers no authority for
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 25

expanding a judgment in this manner to unasserted claims
under the present circumstances. Therefore, we remand to
allow the district court to correct this clerical error.
CONCLUSION
For the reasons above, we affirm the district court’s
conclusion regarding § 101 and noninfringement as to the
claims at issue, but vacate and remand for the limited pur-
pose of correcting the judgment as to unasserted claims.
AFFIRMED-IN-PART, VACATED-IN-PART, AND
REMANDED
COSTS
The parties shall bear their own costs.
 NOTE: This disposition is nonprecedential.

United States Court of Appeals
for the Federal Circuit
______________________

INO THERAPEUTICS LLC, MALLINCKRODT
HOSPITAL PRODUCTS INC., MALLINCKRODT
HOSPITAL PRODUCTS IP LTD.,
Plaintiffs-Appellants

v.

PRAXAIR DISTRIBUTION INC., PRAXAIR INC.,
Defendants-Appellees
______________________

2018-1019
______________________

Appeal from the United States District Court for the
District of Delaware in No. 1:15-cv-00170-GMS, Judge
Gregory M. Sleet.
______________________
NEWMAN, Circuit Judge, concurring-in-part, dissenting-in-
part.
I concur in correction of the technical error, where the
district court included in its decision some claims that were
not there at issue. However, I respectfully dissent from the
majority’s rulings that the claims at issue are ineligible for
patenting under Section 101. The claims are for a method
of medical treatment—a class of subject matter whose eli-
gibility under section 101 is established by precedent.
2 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

The claimed inventions are for a method of treatment
of hypoxic respiratory failure in neonates, and an appa-
ratus for administering dosages of gaseous nitric oxide for
this purpose. INO and Mallinckrodt scientists discovered
the relationship of inhaled nitric oxide to pulmonary edema
in certain infants, and also discovered why certain infants
experience adverse effects. These scientists then developed
a method and apparatus of treatment, avoiding adverse
events.
The method that is described and claimed does not ex-
ist in nature; it was designed by and is administered by
humans. However, the majority holds that this method is
ineligible for patenting because the claims are directed to
a “natural phenomenon.” Maj. Op. at 8–9 (“The inventors
observed an adverse event that iNO gas causes for certain
patients. The patent claim does no more than add an in-
struction to withhold iNO treatment from the identified pa-
tients . . . so it covers a method in which, for the iNO-
excluded patients, the body’s natural processes are simply
allowed to take place.”). The majority does not
acknowledge that the claimed multi-step method of treat-
ment of hypoxic respiratory failure does not occur in na-
ture. 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.
Mallinckrodt states that: “It would be remarkable and
unprecedented to conclude that a new treatment protocol
that is capable of reducing the incidence of severe adverse
events by as much as 90% is not inventive.” Appellants Br.
46. The majority’s holding contravenes the section 101
guidance of the Supreme Court, and directly contradicts
this court’s precedent applying section 101 to methods of
medical treatment. The Court in Mayo Collaborative Ser-
vices v. Prometheus Laboratories, Inc., 566 U.S. 66 (2012),
cautioned against misapplication of its holding,
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 3

reaffirming that a “new way of using an existing drug” is
eligible for patenting under section 101. Id. at 87. My col-
leagues nonetheless hold that since the effect of nitric oxide
is “human physiology,” Maj. Op. at 4, and since physiologic
response is a natural phenomenon, this method of treat-
ment is ineligible for patenting. Id. at 8–9.
Heretofore, Federal Circuit precedent has been reason-
ably consistent in holding that methods of medical treat-
ment are eligible for patenting. See Athena Diagnostics,
Inc. v. Mayo Collaborative Servs., LLC, 927 F.3d 1333,
1367–68 (Fed. Cir. 2019) (Newman, J., dissenting from de-
nial of rehearing en banc) (collecting cases on eligible meth-
ods of treatment and ineligible methods of diagnosis). The
subject matter herein routinely complies with section 101;
the court mis-steps in holding that “[t]he natural phenom-
enon here is undisputed,” whereby the method of treatment
is also deemed to be a natural phenomenon. Maj. Op. at 9.
Mallinckrodt’s method of treatment may or may not
pass the tests of sections 102 or 103, 1 but this court’s prec-
edent and that of the Supreme Court do not exclude meth-
ods of treatment from access to the patent system under
section 101. Today’s change of law adds to the incon-
sistency and unpredictability of this area of patent-sup-
ported innovation.
The INOT22 Study led to the claimed method
Treatment of neonates with gaseous nitric oxide was
approved by the FDA in 1999 for “the treatment of term

1 In a separate proceeding, the Patent Trial and Ap-
peal Board in Inter Partes Review held invalid the claims
of one of the patents here in suit, on the ground of obvious-
ness in view of prior art, section 103. The Federal Circuit
affirmed. Praxair Distribution, Inc. v. Mallinckrodt Hosp.
Prods. IP Ltd., 890 F.3d 1024 (Fed. Cir. 2018).
4 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

and near-term . . . neonates having hypoxic respiratory fail-
ure associated with clinical or echocardiographic evidence
of pulmonary hypertension.” ’741 patent, col. 1, ll. 20–24.
The patent explains that the treatment was contraindi-
cated for neonates who were known as dependent on right-
to-left shunting of blood. Id., col. 3, ll. 53–56.
In 2004 Mallinckrodt sponsored a clinical study known
as INOT22, seeking to understand the occasional severe
adverse effects of nitric oxide, including pulmonary edema
and death. Id., col. 12, ll. 49–58. The study led to under-
standing the relation among left ventricular dysfunction,
pulmonary capillary wedge pressure, and the adverse
events. Id., col. 12, ll. 55–61. Mallinckrodt then designed
a treatment protocol for neonates that reduced the adverse
events. In 2009 the FDA approved this protocol, which is
the basis of the patents in suit, and Praxair’s ANDA and
this Hatch-Waxman litigation.
Claim 1 of the ’741 patent is deemed representative of
the method-of-treatment claims.
1. A method of treating patients who are candi-
dates for inhaled nitric oxide treatment, which
method reduces the risk that inhalation of nitric
oxide gas will induce an increase in pulmonary ca-
pillary wedge pressure (PCWP) leading to pulmo-
nary edema in neonatal patients with hypoxic
respiratory failure, the method 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 plu-
rality does not have left ventricular dysfunction;
(c) determining that a second patient of the plu-
rality has left ventricular dysfunction, so is at par-
ticular risk of increased PCWP leading to
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 5

pulmonary edema upon treatment with inhaled ni-
tric oxide;
(d) administering 20 ppm inhaled nitric oxide
treatment to the first patient; and
(e) excluding the second patient from treat-
ment with inhaled nitric oxide, based on the deter-
mination 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 claims recite a multi-step method of administering in-
haled nitric oxide so that patients with left ventricular dys-
function are at reduced risk of adverse events. This
method is not a law of nature, it is not a natural phenome-
non.
The majority’s argument that a method of treatment of
an affliction affecting human physiology is ineligible under
section 101 contravenes precedent. See, e.g., Rapid Litig.
Mgmt. Ltd. v. CellzDirect, Inc., 827 F.3d 1042, 1048–49
(Fed. Cir. 2016) (method of treating disease “to achieve ‘a
new and useful end,’ is precisely the type of claim that is
eligible for patenting” (quoting Alice Corp. Pty. Ltd. v. CLS
Bank Int’l, 573 U.S. 208, 217 (2014))). My colleagues
acknowledge that the claims include “[a] treatment step of
administering,” Maj. Op. at 11, but state that this step is
“not the focus of the claimed invention,” id., and that “[t]he
claimed invention is focused on screening for a natural
law,” id. at 14–15. However, patent eligibility is deter-
mined not for isolated steps, but for the claimed invention
as a whole. Eligibility does not depend on whether some of
the claim steps were known. The Court reiterated in Dia-
mond v. Diehr, 450 U.S. 175 (1981):
In determining the eligibility of respondents’
claimed process for patent protection under § 101,
their claims must be considered as a whole. It is
6 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

inappropriate to dissect the claims into old and new
elements and then to ignore the presence of the old
elements in the analysis.
Id. at 188; see Parker v. Flook, 437 U.S. 584, 594 (1978)
(“[A] patent claim must be considered as a whole.”); Aro
Mfg. Co. v. Convertible Top Replacement Co., 365 U.S. 336,
344 (1961) (“[I]f anything is settled in the patent law, it is
that the combination patent covers only the totality of the
elements in the claim and that no element, separately
viewed, is within the grant.”). The majority’s analysis is an
explicit departure from this rule.
The majority’s ruling conflicts with extensive
precedent
Heretofore, this court has appropriately viewed section
101 eligibility for method-of-treatment inventions. See,
e.g., Vanda Pharm. Inc. v. West-Ward Pharm. Int’l Ltd.,
887 F.3d 1117 (Fed. Cir. 2018) (method of treatment of
schizophrenia with the drug iloperidone where the dose is
adjusted based on whether the patient is a CYP2D6 poor
metabolizer); Nat. Alternatives Int’l, Inc. v. Creative Com-
pounds, LLC, 918 F.3d 1338 (Fed. Cir. 2019) (method of in-
creasing athletic performance by administering beta-
alanine); Endo Pharm. Inc. v. Teva Pharm. USA, Inc., 919
F.3d 1347 (Fed. Cir. 2019) (method of treating patients
with oxymorphone based on the discovery that patients
with impaired kidney function need less oxymorphone for
pain relief). Despite precedent, the majority today holds
that this method-of-treatment is not patent-eligible under
section 101.
Section 101 states the eligibility for patenting of “any
new and useful process, machine, manufacture, or compo-
sition of matter, or any new and useful improvement
thereof,” while “subject to the conditions and requirements
of this title.” The purpose of section 101 is to introduce the
statute and define the scope of its subject matter, as distin-
guished from the subject matter of copyright, also
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 7

authorized in Article I, Section 8, Clause 8 of the Constitu-
tion. In turn, eligible subject matter is reviewed for com-
pliance with the conditions of patentability in sections 102,
103, 112, and the rest of Title 35.
The majority attempts to meet these concerns by stat-
ing “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.” Maj. Op. at
22. This disclaimer appears at the end of a lengthy exposi-
tion, whose wide-ranging pronouncements of law and pol-
icy are not tied to narrow circumstances or claims. The
persistent theme of the majority’s analysis is that if a claim
contains limitations that concern human physiology, ineli-
gibility arises under section 101, whether or not the
claimed method of medical treatment meets the require-
ment of patentability.
The majority’s broad pronouncement of ineligibility of
medical treatment that relates to human physiology not
only contravenes precedent, but contravenes the national
interest in achieving new methods of medical treatment
with the assistance of the patent incentive.
The policy of patent-supported innovation
My colleagues state that the new method presented by
INO and Mallinckrodt is ineligible under section 101 be-
cause it is “broadly preemptive of uses of the natural phe-
nomenon,” Maj. Op. at 21, and “risks monopolizing”
information. Id. at 10. We are not told how this method
preempts any known or unknown uses of this “natural phe-
nomenon” or forecloses use of scientific information.
The patents at issue arose from discovery of the rela-
tion among left ventricular dysfunction, gaseous nitric ox-
ide, and pulmonary edema—a discovery disclosed in the
patent for all to understand and study and evaluate and
test and improve upon. The Court has reiterated, “the fed-
eral patent system thus embodies a carefully crafted
8 INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC.

bargain for encouraging the creation and disclosure of new,
useful, and nonobvious advances in technology and design
in return for the exclusive right to practice the invention
for a period of years.” Bonito Boats, Inc. v. Thunder Craft
Boats, Inc., 489 U.S. 141, 150–51 (1989). See J.E.M. Ag
Supply, Inc. v. Pioneer Hi–Bred Int’l, Inc., 534 U.S. 124, 142
(2001) (“The disclosure required by the Patent Act is ‘the
quid pro quo of the right to exclude.’” (quoting Kewanee Oil
Co. v. Bicron Corp., 416 U.S. 470, 484 (1974))).
My colleagues’ position that patents impede scientific
and technologic advance ignores the principle, first stated
in Whittemore v. Cutter, 29 F. Cas. 1120, 1121 (C.C.D.
Mass. 1813), that: “It could never have been the intention
of the legislature to punish a man, who constructed such a
machine merely for philosophical experiments, or for the
purpose of ascertaining the sufficiency of the machine to
produce its described effects.” This common-law research
exemption was remarked in Integra Lifesciences I, Ltd. v.
Merck KGaA, 331 F.3d 860, 875 (Fed. Cir. 2003) (Newman,
J., dissenting) (“Today’s accelerated technological advance
is based in large part on knowledge of the details of pa-
tented inventions and how they are made and used. Prohi-
bition of research into such knowledge cannot be squared
with the framework of the patent law.”). See also Giles S.
Rich, Principles of Patentability, 28 Geo. Wash. L. Rev.
393, 400 (1960) (“It should never be forgotten that patented
inventions are published and become a part of the technical
literature. This publication itself promotes progress in the
useful arts and it is the prospect of patent rights which in-
duces disclosure and the issuance of the patent which
makes it available.”) (emphasis original).
Patents provide the economic incentive for medical sci-
entists and industries to devise new treatments to serve
the afflicted public. My colleagues’ holding that such in-
ventions are broadly ineligible for patenting, will simply
add disincentive to medical advance. From my colleagues’
holding that this improved method of treatment of
INO THERAPEUTICS LLC v. PRAXAIR DISTRIBUTION INC. 9

neonates having left ventricular dysfunction is ineligible
under section 101, I respectfully dissent.