Federal Circuit disposition — 23-2338

NOTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
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IN RE: MATTHEW MCLEAY,
Appellant
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2023-2338
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Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 17/231,735.
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Decided: February 18, 2025
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BARTHOLOMEW L. M CLEAY, Kutak Rock LLP, Omaha,
NE, argued for appellant. Also represented by RYAN
STEVEN H INDERLITER , Kansas City, MO.
SARAH E. CRAVEN , Office of the Solicitor, United States
Patent and Trademark Office, Alexandria, VA, argued for
appellee Coke Morgan Stewart. Also represented by
M ICHAEL S. FORMAN , AMY J. NELSON , FARHEENA Y ASMEEN
RASHEED .
______________________
Case: 23-2338 Document: 43 Page: 1 Filed: 02/18/2025

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IN RE: MCLEAY 2
Before M OORE, Chief Judge, STOLL, Circuit Judge, and
G ILSTRAP, Chief District Judge.1
G ILSTRAP, Chief District Judge.
Matthew McLeay appeals from a decision of the United
States Patent Trial and Appeal Board (the “Board”). The
Board affirmed an Examiner’s rejection of claims 20–24 of
U.S. Patent Application No. 17/231,735 (the “Application”)
as unpatentable for lack of enablement under 35 U.S.C. §
112(a). For the reasons provided below, we affirm.
BACKGROUND
On April 15, 2021, McLeay filed the Application. The
Application discloses using ribavirin, amongst other medi-
cations, for the treatment of certain respiratory conditions.
The Application included 20 method of treatment claims,
including three independent claims. Appx83–85. McLeay
amended claim 20, which as amended recites the following:
20. A method of treating a SARS-CoV-2 lung infec-
tion in a patient in need thereof comprising admin-
istering to a lung of said patient by inhalation a
liquid aerosol composition comprising >50% (w/w)
water and <50% (w/w) ribavirin, wherein said liq-
uid aerosol is delivered to the lung with a nebu-
lizer.
Appx3 (alteration removed).2 Claims 21–24 each depend
from claim 20.
During prosecution, the Examiner issued a Final Office
Action that rejected claims 20–24 for lack of enablement.
1 Honorable Rodney Gilstrap, Chief Judge, United
States District Court for the Eastern District of Texas, sit-
ting by designation.
2 All limitations of claim 20 were disclosed in the Ap-
plication as-filed. See Appx84–85.
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IN RE: MCLEAY 3
Particularly relevant here, the Examiner found that the
breadth of the claims was not fully enabled by the Applica-
tion because there is insufficient disclosure of the claimed
composition. Appx988. Further, the Examiner found that
the Application admits “that the use of ribavirin in treating
COVID-19 is not expected to be successful by skilled pul-
monologists and infectious disease specialists.” Appx989.
In view of this finding, the Examiner found that “[o]ne
skilled in the art cannot readily anticipate the effect of ad-
ministering to the lung infected with SARS-CoV-2 an aer-
osolized liquid comprising >50% water and <50% ribavirin,
and thus there is lack of predictability in the art.” Appx990.
The Examiner also found that the Application fails to dis-
close whether the claimed compound is effective in treating
a SARS-CoV-2 lung infection in a patient. Appx990–91. Fi-
nally, the Examiner found that the quantity of experimen-
tation needed to make or use the claimed invention “would
be significant.” Appx991.
In the Final Office Action, the Examiner also rejected
McLeay’s argument that the prior art reference Gilbert and
McLeay3 discloses how to make, use, and administer the
claimed composition. The Examiner found that Gilbert and
McLeay “teaches treatment of influenza A virus infections
using MegaRibavirin aerosol, and the treatment of influ-
enza A is not indicative of its effectiveness against SARS-
CoV-2 lung infection.” Appx993. McLeay also argued that
Messina,4 a post-filing date reference, established that the
administration “of aerosolized ribavirin according to the
3 Brian E. Gilbert and Matthew T. McLeay, MegaRi-
bavirin Aerosol for the Treatment of Influenza A Virus In-
fections in Mice, 78 Antiviral Res. 223–29 (2008) (Appx955–
61). 4 Messina et al., Ribavirin Aerosol in the Treatment
of SARS-CoV-2: A Case Series, 10 Infect. Dis. Ther. 2791-
804 (2021) (Appx962–75).
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IN RE: MCLEAY 4
subject patent application as disclosed in the written de-
scription has been demonstrated to be efficacious in the
treatment of [five] patients with COVID-19.” Appx945. The
Examiner found this argument unpersuasive since Mes-
sina does not enable the full scope of the claims (i.e., a com-
position comprising less than 50% ribavirin). Appx56–57.
McLeay appealed the Examiner’s decision to the Board.
The Board found “that a preponderance of the evidence
supports Examiner’s analysis of the Wands factors and
adopt[ed] them as” their own. Appx27. The Board further
denied McLeay’s rehearing request and did not modify its
decision. Appx2.
McLeay timely appeals to this court. We have jurisdic-
tion under 28 U.S.C. § 1295(a)(4)(A).
D ISCUSSION
“Whether a claim satisfies the enablement require-
ment is a question of law that may be based on underlying
factual findings.” Medytox, Inc. v. Galderma S.A., 71 F.4th
990, 996 (Fed. Cir. 2023) (citing Alcon Rsch. Ltd. v. Barr
Lab’ys, Inc., 745 F.3d 1180, 1188, 1190 (Fed. Cir. 2014)).
We review the Board’s legal conclusions de novo and its fac-
tual findings for substantial evidence. In re Kotzab, 217
F.3d 1365, 1369 (Fed. Cir. 2000). “If the evidence in record
will support several reasonable but contradictory conclu-
sions, we will not find the Board’s decision unsupported by
substantial evidence simply because the Board chose one
conclusion over another plausible alternative.” In re Jolley,
308 F.3d 1317, 1320 (Fed. Cir. 2002).
Section 112(a) provides in relevant part that
[t]he specification shall contain a written de-
scription of the invention, and of the manner
and process of making and using it, in such
full, clear, concise, and exact terms as to ena-
ble any person skilled in the art to which it
pertains, or with which it is most nearly con-
nected, to make and use the same.
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IN RE: MCLEAY 5
35 U.S.C. § 112(a). “The specification must enable the full
scope of the invention as defined by its claims, allowing for
a reasonable amount of experimentation.” Baxalta Inc. v.
Genentech, Inc., 81 F.4th 1362, 1364–65 (Fed. Cir. 2023)
(quoting Amgen Inc. v. Sanofi, 598 U.S. 594, 610–12 (2023))
(cleaned up).
I
McLeay argues the Board erred in concluding that un-
due experimentation is required to practice the claimed in-
vention. To start, the Board found that a person of ordinary
skill in the art would not have expected that ribavirin
would be effective in treating a SARS-CoV-2 lung infection,
and therefore, the quantity of experimentation needed to
practice the claimed method, absent some disclosure to the
contrary, would be considerable. Appx45. The Board’s fact
findings are supported by substantial evidence, including
that the Application itself recognized that Ribavirin’s “use
in treating COVID-19 is not expected by skilled pul-
monologists and infectious disease specialists to be success-
ful in treating COVID-19.” Appx447–49 (collecting articles
that concluded that ribavirin would not be effective for
treating patients infected with COVID-19).
Nor do the portions of the Application cited by McLeay
provide guidance to a person of ordinary skill in the art as
to how to arrive at the claimed invention without undue
experimentation. Notably, McLeay relies upon “Example
7” of the Application, which is titled “Coronavirus infec-
tion” and describes treating a single patient exhibiting
“symptoms of fever” with dry powder ribavirin. Appx478–
79. The Board found that the Application’s Example 7 does
not describe treating a SARS-CoV-2 lung infection with the
composition recited in claim 20, as it fails to describe treat-
ment “with a liquid aerosol comprising >50% (w/w) water
and < 50% of said ribavirin and excipient.” Appx31. This
finding is supported by substantial evidence. Appx478–79.
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IN RE: MCLEAY 6
Additionally, McLeay advances arguments substan-
tially similar to those rejected by the Board that references
outside the Application enable claim 20. This court is sim-
ilarly unpersuaded by these arguments. With respect to the
Gilbert and McLeay prior art reference and the post-filing
Messina reference, neither discloses the up-to-50% range
of ribavirin recited by claim 20. At best, these references
disclose 2%, 6%, and 10% ribavirin. Gilbert and McLeay
discloses treating patients infected with influenza A—not
a SARS-CoV-2 lung infection—with compositions compris-
ing 2%, 6%, and 10% doses of ribavirin. Appx958. Messina
discloses treating patients infected with a SARS-CoV-2
lung infection, but only with a composition comprising 10%
ribavirin. Appx964. There is no disclosure of record, pre- or
post-Application filing, that administration of a liquid aer-
osol composition comprising over 10% ribavirin—let alone
one as high as 49.99% ribavirin—may effectively treat a
SARS-CoV-2 lung infection. Accordingly, substantial evi-
dence supports the Board’s conclusion that the Application
does not disclose that the full range recited in claim 20 is
effective for treating a SARS-CoV-2 lung infection.5
II
This court has held that “[e]nablement is closely re-
lated to the requirement for utility.” In re ’318 Pat. In-
fringement Litig., 583 F.3d 1317, 1323 (Fed. Cir. 2009).
Moreover, this Court has held that “[i]f a patent claim fails
to meet the utility requirement because it is not useful or
operative, then it also fails to meet the how-to-use aspect
of the enablement requirement.” Process Control Corp. v.
HydReclaim Corp., 190 F.3d 1350, 1358 (Fed.Cir.1999).
Here, the Board correctly found that McLeay has failed to
show that claim 20 meets the how-to-use aspect of the en-
ablement requirement because, as explained above, the full
5 McLeay does not separately argue that the Board
erred with respect to dependent claims 21–24.
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IN RE: MCLEAY 7
scope of the claim is not “useful or operative.” This require-
ment prevents McLeay from “patenting [] a mere research
proposal” for possibly effective amounts of ribavirin for
treating a SARS-CoV-2 lung infection. ’318 Pat. Litig., 583
F.3d at 1324.
However, we reject the Board’s overbroad contention
that the claim is not enabled because the Application
“lacked any evidence of ribavirin’s efficacy against COVID-
19.” Appellee’s Br. at 24. While utility informs a court in
making an enablement determination, a claim’s utility
alone should not end the enablement inquiry. In this case,
claim 20’s fatal flaw is that there is substantial evidence
for the Board’s fact findings underlying its conclusion that
practicing the full scope of the claimed range would require
undue experimentation.
CONCLUSION
We have considered McLeay’s remaining arguments
but find them unpersuasive. For the reasons stated above,
we affirm the Board’s finding that claims 20–24 are not en-
abled.
AFFIRMED
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