Knoa Pharma LLC, Knoa Pharmaceuticals LLC, Fka Purdue Pharmaceuticals L.p. v. Accord Healthcare, Inc.

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
KNOA PHARMA LLC, KNOA PHARMACEUTICALS
LLC, FKA PURDUE PHARMACEUTICALS L.P.,
Plaintiffs-Appellants
v.
ACCORD HEALTHCARE, INC.,
Defendant-Appellee
______________________
2025-1060
______________________
Appeal from the United States District Court for the
District of Delaware in No. 1:22-cv-00913-WCB, Circuit
Judge William C. Bryson.
______________________
Decided: June 8, 2026
______________________
MARGARET U PSHAW , Latham & Watkins LLP, Wash-
ington, DC, argued for plaintiffs-appellants. Also repre-
sented by G REGORY G. G ARRE , ALEXANDER G. SIEMERS ;
D ANIEL BROWN, New York, NY; G REGORY A. CASTANIAS ,
J ENNIFER L. SWIZE, Jones Day, Washington, DC; G ASPER
L AROSA, J OHN J OSEPH N ORMILE, J R., New York, NY; P ABLO
D ANIEL HENDLER, Potomac Law Group PLLC, New York,
NY.
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KNOA PHARMA LLC v. ACCORD HEALTHCARE, INC. 2
BEN MAHON, McAndrews, Held & Malloy, Ltd., Chi-
cago, IL, argued for defendant-appellee. Also represented
by RAJENDRA A. CHIPLUNKAR, ALEJANDRO MENCHACA .
______________________
Before H UGHES and S TOLL , Circuit Judges, and SEEBORG,
Chief District Judge.†
SEEBORG, Chief District Judge.
In this patent case, appellants1 challenge the trial
court’s finding of invalidity on grounds of obviousness. The
focus of the litigation is the inventors’ claim to have devel-
oped a non-obvious product-by-process for an “abuse-deter-
rent” pill containing oxycodone hydrochloride, often known
simply as “oxycodone.”
Oxycodone is a synthetic opioid, developed in 1916, in
an effort to find a less addictive alternative to heroin and
morphine for soldiers in World War I. At lower doses, opi-
oids have analgesic (pain relieving) effects. At higher doses,
† Honorable Richard Seeborg, Chief District Judge,
United States District Court for the Northern District of
California, sitting by designation.
1 The original appellants in this action were Purdue
Pharma L.P. and Purdue Pharmaceuticals L.P. (collec-
tively, “Purdue”). After oral argument, and as a result of
developments in Purdue’s bankruptcy proceedings, we
have granted a motion by Knoa Pharma LLC (“Knoa”) to
be substituted for Purdue Pharma L.P. and to recognize
that the name of Purdue Pharmaceuticals L.P. has been
changed to Knoa Pharmaceuticals LLC. Knoa asserts it
now holds the rights to the patent at issue in this appeal,
and there is no evidence to the contrary. For convenience,
we will continue to refer to the appellants and patent
holder as “Purdue,” in the singular.
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PURDUE PHARMA L . P. v. ACCORD HEALTHCARE, INC. 3
they have euphoric effects, which can lead to abuse.
J.A. 2471.
Following a bench trial, the trial court held all the as-
serted claims of U.S. Patent No. 11,304,908 (“the ’908 pa-
tent”) invalid on obviousness grounds. Purdue Pharma L.P.
v. Accord Healthcare Inc., No. CV 22-913-WCB, 2024 WL
4120717, at *23 (D. Del. Sept. 9, 2024) (“Purdue”). One in-
dependent claim and several dependent claims were in dis-
pute. The patent holder appeals as to only one dependent
claim, claim 18. That claim incorporates a limitation set
out in the claim from which it depends, claim 17, that the
abuse-deterrent oxycodone pills be heated “in a coating
pan” for a specified approximate minimum time period and
at an approximate minimum temperature. ’908 patent
164:47–48.
The relevant prior art taught heating the pills in a tab-
let press, which cannot readily produce pills in large quan-
tities. The trial court found that use of coating pans to heat
the tablets would have been an obvious alternative, as coat-
ing pans can treat large numbers of tablets at a time, and
were known devices already employed in the production of
pharmaceutical tablets, albeit for other purposes.
Purdue timely appealed. We have jurisdiction under
28 U.S.C. § 1295(a)(1). The trial court’s factual determina-
tions are free from clear error. On de novo review of the
trial court’s legal conclusion of obviousness, we affirm.
BACKGROUND
In 1995, Purdue developed and obtained FDA approval
for OxyContin, a pill with oxycodone as the active ingredi-
ent. The oxycodone in the pill was contained within a chem-
ical matrix of an inert material that breaks down slowly
over time in the body, allowing the release of the oxycodone
over an extended period—e.g., 12 hours.
Not long after the original OxyContin was available on
the market, it became apparent that some people were
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KNOA PHARMA LLC v. ACCORD HEALTHCARE, INC. 4
abusing the tablets by crushing them and snorting the res-
idue, or by mixing the crushed tablets with liquid and in-
jecting the solution. Through these methods, abusers were
able to experience the effects of an entire dose of oxycodone
in a short period of time, leading to a more pronounced eu-
phoric effect than if the pill released the drug over several
hours, as designed.
Purdue began investigating whether it could produce a
form of OxyContin less susceptible to abuse. Purdue con-
sidered two main approaches, either adding an “antago-
nist” to the formulation that would render the drug
unusable for abuse or making the tablets tamper-resistant
so that abusers could not readily crush the tablets to re-
lease the drug inside.
In February of 2005, the United States Patent and
Trademark Office published United States Patent Applica-
tion 2005/0031546 A1 (“Bartholomäus”), filed by Johannes
Bartholomäus and Heinrich Kugelmann, which was di-
rected to drug-containing tablet formulations made tam-
per-resistant by hardening the tablets. The application was
later assigned to Grunenthal GmbH, a German pharma-
ceutical company. Bartholomäus teaches using an opioid
drug formulation containing polyethylene oxide (“PEO”)
having a specified molecular range, press-forming the for-
mulation, and heating it to the melting point of the PEO
through preceding, simultaneous, or subsequent exposure
to heat.
Bartholomäus reports that the resulting tablets were
extremely hard. The tablets did not break, even when ex-
posed to a force of 500 Newtons. In addition, while the tab-
lets could be cut into pieces having an edge length as small
as about 2 millimeters, they could not be pulverized. When
the pieces were combined with water, a highly viscous gel
was formed that could not easily be pressed through an in-
jection needle. J.A. 8132.
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PURDUE PHARMA L . P. v. ACCORD HEALTHCARE, INC. 5
In April of 2005, one of the inventors on Purdue’s
’908 patent, Dr. Richard Mannion, reviewed the Barthol-
omäus application. Mannion and other Purdue employees
then visited the Grunenthal facilities to learn more about
Bartholomäus’s approach. Although Purdue argues
Dr. Mannion initially rejected pursuing a PEO-based for-
mulation, within months thereafter, Purdue had success-
fully produced a crush-resistant product by curing PEO
tablets in a manner generally similar to that described in
Bartholomäus.
As noted, the method described in Bartholomäus cured
the tablets in a tablet press, a device that was not readily
scalable for the purpose of producing commercial quanti-
ties of tablets. In contrast, Purdue used a different heating
mechanism to cure its tablets: a device known as a coating
pan, which could process hundreds of tablets at a time.
Coating pans, as suggested by their name, had tradi-
tionally been used to apply coatings to tablets, presumably
as the final step in production. Although the coating pro-
cess includes applying heat to dry the sprayed-on coating,
generally the goal was to avoid heating the tablets to the
point that it would cause any change in their properties. As
Purdue puts it, coating pans had only ever been used to
coat tablets, not to cure them. Appellants’ Br. 2.
In August 2006, Purdue filed a provisional patent ap-
plication. The ’908 patent, entitled “tamper resistant dos-
age forms,” claims priority to that provisional patent
application.
Purdue later sought FDA approval for its abuse-re-
sistant oxycodone formulation, asserting it was bioequiva-
lent to the original OxyContin. In 2010, the FDA approved
the new formulation. Eventually, the FDA also approved
Purdue’s application to have the OxyContin label revised
to reflect that the new tablets were abuse-deterrent. At
that time, the FDA required Purdue to remove the original
formulation of OxyContin from the market.
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KNOA PHARMA LLC v. ACCORD HEALTHCARE, INC. 6
Subsequently, defendant-appellee Accord Health Care,
Inc. (Accord) filed an Abbreviated New Drug Application
(ANDA) seeking the FDA’s approval to market a generic
version of Purdue’s tamper-resistant OxyContin product.
In response, Purdue filed an action in the District of Dela-
ware seeking a declaration that Accord’s proposed generic
would infringe the ’908 patent. Accord responded by stipu-
lating to infringement but asserted that the ’908 patent
was invalid as obvious.
The district court held a bench trial in February of
2024. The court found the asserted claims of the ’908 patent
invalid as obvious, in light of Bartholomäus.2
As noted, the only claim in dispute in this appeal is de-
pendent claim 18, which, of course, must be read in con-
junction with the claims from which it depends, specifically
2 Prior to this case, Purdue brought a separate action
against Accord, asserting patents from the same family as
the ’908 patent. See Purdue Pharma L.P. v. Accord
Healthcare Inc., 669 F. Supp. 3d 286 (D. Del. 2023) (“Accord
I”). That case involved three patents directed to tamper-
resistant tablet formulations, together with two other un-
related patents. The patents related to tamper-resistant
tablets were all found invalid as obvious, largely in light of
Bartholomäus.
At the time of the trial court decision in this case, Ac-
cord I was still on appeal. The district court’s decision has
now been affirmed. See Purdue Pharma L.P. v. Accord
Healthcare, Inc., No. 2023-1953, 2024 WL 5244764, at *1
(Fed. Cir. Dec. 30, 2024). Although the trial court found ad-
ditional support in Accord I for certain of its findings in this
matter, neither the trial court decision nor the appellate
opinion in that case are directly relevant to the specific is-
sues raised by Purdue in this appeal and neither party ar-
gues otherwise.
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PURDUE PHARMA L . P. v. ACCORD HEALTHCARE, INC. 7
independent claim 1 and dependent claim 17. The relevant
claims are as follows, with the disputed language empha-
sized:
1. A solid oral extended release pharmaceutical
dosage form, comprising a shaped, convection
heated, and cooled extended release matrix, said
matrix comprising at least one polyethylene oxide
(PEO) having, based on rheological measurements,
an approximate molecular weight of at least
800,000, and at least one opioid analgesic, wherein
(a) the shaped matrix is convection heated to an el-
evated temperature that is at least the softening
temperature of said PEO for a time period of at
least about 1 minute and thereafter cooled; and (b)
a plurality of convection heated particles of PEO
adhere to or fuse with each other within the matrix.
17. The dosage form of claim 1, wherein the ex-
tended release matrix is shaped to form a tablet
and heated in a coating pan; said time period is at
least about 5 minutes; and said elevated tempera-
ture is at least about 60° C.
18. The dosage form of claim 17, wherein the
opioid analgesic is oxycodone or a pharmaceutically
acceptable salt thereof.
The judgment under appeal finds claim 18 invalid be-
cause the element “heated in a coating pan” set out in claim
17, from which 18 depends, would have been an obvious
modification to the teachings of Bartholomäus that a per-
son of ordinary skill in the art would have been motivated
to make. The central issue on appeal is whether the district
court erred in holding claim 18 obvious.
L EGAL STANDARDS
“Obviousness is a question of law, reviewed de novo,
based upon underlying factual questions which are re-
viewed for clear error following a bench trial.” Aventis
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KNOA PHARMA LLC v. ACCORD HEALTHCARE, INC. 8
Pharma Deutschland GmbH v. Lupin, Ltd., 499 F.3d 1293,
1300 (Fed. Cir. 2007) (cleaned up). “The presence or ab-
sence of a motivation to arrive at the claimed invention,
and of a reasonable expectation of success in doing so, are
questions of fact.” Amgen Inc. v. Sandoz Inc., 66 F.4th 952,
960 (Fed. Cir. 2023). “A factual finding is only clearly erro-
neous if, despite some supporting evidence, we are left with
the definite and firm conviction that a mistake has been
made.” Merck Sharp & Dohme Corp. v. Hospira, Inc.,
874 F.3d 724, 728 (Fed. Cir. 2017) (citations omitted).
“A patent for a claimed invention may not be ob-
tained . . . if the differences between the claimed invention
and the prior art are such that the claimed invention as a
whole would have been obvious before the effective filing
date of the claimed invention . . . .” 35 U.S.C. § 103. “Obvi-
ousness is based on underlying factual findings, including:
(1) the level of ordinary skill in the art; (2) the scope and
content of the prior art; (3) the differences between the
claims and the prior art; and (4) secondary considerations
of nonobviousness, such as commercial success, long-felt
but unmet needs, failure of others, and unexpected re-
sults.” Prometheus Labs., Inc. v. Roxane Labs., Inc.,
805 F.3d 1092, 1097 (Fed. Cir. 2015) (first citing KSR Int’l
Co. v. Teleflex, Inc., 550 U.S. 398, 406 (2007); and then cit-
ing Graham v. John Deere Co., 383 U.S. 1, 17–18 (1966)).
D ISCUSSION
I.
To establish obviousness, Accord was required to prove
by clear and convincing evidence that a person of ordinary
skill in the art “would have been motivated to combine or
modify the teachings in the prior art” to arrive at the
claimed invention. Regents of the Univ. of Cal. v. Broad
Inst., Inc., 903 F.3d 1286, 1291 (Fed. Cir. 2018). The ulti-
mate touchstone of the “motivation to combine” inquiry is
not whether “one of ordinary skill in the art could combine”
a number of prior art references, but whether “they would
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PURDUE PHARMA L . P. v. ACCORD HEALTHCARE, INC. 9
have been motivated to do so.” InTouch Techs., Inc. v. VGO
Commc’ns, Inc., 751 F.3d 1327, 1352 (Fed. Cir. 2014). The
party seeking to invalidate a patent must provide “‘reason-
ing with some rational underpinning’” for combining the
prior art, in order to avoid “the pitfalls of hindsight that
belie a determination of obviousness.” Innogenetics, N.V. v.
Abbott Laboratories, 512 F.3d 1363, 1373 (Fed. Cir. 2008)
(quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)).
At trial, Accord presented evidence through its expert,
Dr. Leah Appel. She testified that while Bartholomäus
teaches an abuse-proofed PEO oxycodone formulation, the
actual heating device (a manual tablet press heated inside
of a heating cabinet) was not a scalable or commercial so-
lution. Bartholomäus teaches using conductive heating (di-
rect application of heat to the tablets) rather than
convection heating, where heat is transferred through hot
air or another fluid.
Dr. Appel explained how ovens, fluid beds, and coating
pans were capable of handling hundreds of kilograms of
tablets at a time and were also common pieces of equip-
ment found in drug manufacturing facilities. Dr. Appel fur-
ther explained why a coating pan would have been an
especially attractive piece of heating equipment, as it al-
lowed large scale curing, followed by coating, and thus a
person of ordinary skill in the art would have been espe-
cially motivated to use a coating pan to cure Barthol-
omäus’s PEO tablets at scale to maximize manufacturing
efficiency.
The trial court expressly found Dr. Appel’s testimony
to be credible and convincing. Based thereon, the court
made the factual finding that a person of ordinary skill in
the art would have been motivated to modify Bartholomäus
by replacing the tablet press and “curing the tablets in a
convection heating device such as a coating pan.” Purdue,
2024 WL 4120717, at *11.
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KNOA PHARMA LLC v. ACCORD HEALTHCARE, INC. 10
Purdue first contends the court committed legal error
when it allegedly “collapsed” dependent claim 18 into claim
1 by repeatedly referring to the convection heating limita-
tion of claim 1 in conjunction with the “heated in a coating
pan” limitation of claim 18. Appellants’ Br. 4. For example,
the district court observed Dr. Appel had testified that
“convection heating devices such as coating pans, ovens, or
fluid bed dryers, are commonly found in facilities where
pharmaceutical tablets are manufactured, and that there
would be a strong motivation to substitute such de-
vices . . . .” Purdue, 2024 WL 4120717, at *8 (emphasis
added). Purdue appears to be saying it would not be enough
for the court to have concluded that use of a coating pan
was obvious merely because use of some form of convection
heating might have been obvious.
The district court, however, was addressing the valid-
ity both of claim 18 and dependents of claim 21. The de-
pendents of claim 21 did not include a coating pan
limitation, only a convection heating limitation. It was en-
tirely appropriate for the district court to discuss the issues
together, and it always made clear that it was keeping in
mind the coating pan limitation applicable to claim 18.
For example, in summarizing its factual findings, the
court stated, “Bartholomäus expressly discloses all the lim-
itations found in the asserted claims of the ’908 patent ex-
cept for the limitations requiring that the formulation be
cured by convection heating (all asserted claims), that the
heating be performed in a coating pan (claim 18) . . . .” Pur-
due, 2024 WL 4120717, at *11 (emphasis added). The court
did not commit legal error by “collapsing” the relevant
claim limitations.
The remainder of Purdue’s argument consists of listing
the evidence it believes undermines the court’s factual find-
ing of a motivation to use coating pans and complaining
that the court did not address the points it advanced at
trial in what it contends is the requisite detail.
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“Determining the weight and credibility of the evidence
is the special province of the trier of fact.” Inwood Lab’ys,
Inc. v. Ives Lab’ys, Inc., 456 U.S. 844, 856 (1982). Here, the
district court found Dr. Appel’s testimony credible and con-
vincing. “[C]redibility determinations by the trial judge can
virtually never be clear error.” JVW Enters., Inc. v. Interact
Accessories, Inc., 424 F.3d 1324, 1334 (Fed. Cir. 2005) (ci-
tations omitted).
Furthermore, Federal Rule of Civil Procedure 52(a)
does not require “elaborate, detailed findings on every fac-
tual issue raised.” Atlantic Thermoplastics Co. v. Faytex
Corp., 5 F.3d 1477, 1479 (Fed. Cir. 1993). A district court’s
findings of fact are adequate if they are “sufficiently com-
prehensive and pertinent to the issue to form a basis for
the decision.” Medtronic, Inc. v. Daig Corp., 789 F.2d 903,
906 (Fed. Cir. 1986) (quoting Loctite Corp. v. Ultraseal Ltd.,
781 F.2d 861, 873 (Fed. Cir. 1985)). The trial court’s deci-
sion easily meets that standard.
II.
Purdue’s attack on the trial court’s finding that a per-
son of ordinary skill in the art would have had a reasonable
expectation of success with respect to using coating pans
parallels its arguments regarding motivation to combine.
Again, the trial court relied on Dr. Appel’s testimony that
it found credible and convincing, and again Purdue insists
that testimony was too conclusory, and that the court failed
to give sufficient weight to contrary evidence or to engage
sufficiently with all of Purdue’s specific contentions.
As with the motivation to combine issue, Purdue’s in-
sistence that the evidence could have supported a different
result on the issue of reasonable expectation of success is
insufficient to overturn the trial court’s factual findings.
That a contrary conclusion could have been reached does
not meet the “clear error” standard.
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III.
Purdue also asserts that the district court erred in find-
ing that the claimed invention did not meet a long-felt but
unmet need. Before reaching a conclusion on obviousness,
courts analyze “the objective indicia of nonobviousness.”
Leo Pharm. Prods., Ltd. v. Rea, 726 F.3d 1346, 1357–58
(Fed. Cir. 2013). Such indicia “play a critical role in the ob-
viousness analysis,” as their consideration is “crucial in
avoiding the trap of hindsight when reviewing, what oth-
erwise seems like, a combination of known elements.” Id.
at 1358. Among those objective indicia is evidence that the
claimed invention solved “a long felt but unresolved need.”
WBIP, LLC v. Kohler Co., 829 F.3d 1317, 1332 (Fed. Cir.
2016). This “tends to show non-obviousness because it is
reasonable to infer that the need would have not persisted
had the solution been obvious.” Id.; see also, e.g., Amgen,
66 F.4th at 964.
Here, Purdue contended at trial that there was “a long
felt but unresolved need” for an abuse-deterrent oxycodone
tablet. Addressing Purdue’s arguments at length, the trial
court found this alleged need had already been met by Bar-
tholomäus, which disclosed an extended-release opioid
with abuse-deterrent properties. Given Bartholomäus’s
undisputed teachings as set forth above, the district court
did not clearly err in so finding. See, e.g., BTG Int’l Ltd. v.
Amneal Pharms. LLC, 923 F.3d 1063, 1076 (Fed. Cir. 2019)
(where the “Asserted Claims only require an effective treat-
ment for prostate cancer” and other treatments were avail-
able and effective, evidence did not establish long-felt
unmet need).
On appeal, Purdue shifts focus to argue the long-unmet
need was for scalable, commercially practical abuse-deter-
rent tablets. Accord contends this is a new theory, forfeited
by Purdue’s failure to present it to the trial court. We agree.
Even assuming the argument was not forfeited, claim 18 is
directed to a “solid oral extended release pharmaceutical
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dosage form” and does not recite a scalable process. As
such, any long-felt need for a scalable process is not com-
mensurate in scope with the claim. See, e.g., ABT Sys., LLC
v. Emerson Elec. Co., 797 F.3d 1350, 1362 (Fed. Cir. 2015)
(rejecting long-felt need argument that “ignores the scope
of [the] claim”).
CONCLUSION
We have considered Purdue’s remaining arguments
and find them unpersuasive. For the foregoing reasons, we
affirm the district court’s final judgment, finding claim 18
of the ’908 patent invalid as obvious under 35 U.S.C. § 103.
AFFIRMED
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