Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd.

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
AZURITY PHARMACEUTICALS, INC.,
Plaintiff-Appellant
v.
ALKEM LABORATORIES LTD.,
Defendant-Appellee
______________________
2023-1540
______________________
Appeal from the United States District Court for the
District of Delaware in No. 1:19-cv-02100-MSG, Judge
Mitchell S. Goldberg.
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Decided: September 14, 2023
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T UNG O N K ONG, Wilson, Sonsini, Goodrich & Rosati,
PC, San Francisco, CA, argued for plaintiff-appellant. Also
represented by WENDY L. D EVINE, K RISTINA M. HANSON;
K ELSEY CURTIS , RICHARD T ORCZON, Washington, DC.
T IMOTHY H. K RATZ, Kratz & Barry LLP, Atlanta, GA,
argued for defendant-appellee. Also represented by
G EORGE B ARRY , III; MICHAEL P ATRICK H OGAN, Philadel-
phia, PA; R. T OUHEY MYER, Wilmington, DE.
______________________
Case: 23-1540 Document: 35 Page: 1 Filed: 09/14/2023

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AZURITY PHARMACEUTICALS, INC. v.
ALKEM LABORATORIES LTD.
2
Before D YK, HUGHES , and STOLL , Circuit Judges.
D YK, Circuit Judge.
Azurity Pharmaceuticals, Inc. (“Azurity”) appeals a de-
cision of the United States district court for the District of
Delaware determining that claims 16, 18, 22, 23, and 28 of
U.S. Patent No. 10,786,482 and claims 4, 7, 17, and 18 of
U.S. Patent No. 10,918,621 were invalid. We affirm.
BACKGROUND
The ’482 and ’621 patents claim liquid formulations of
enalapril. Enalapril treats high blood pressure and has
long been used in tablet form. Children and elderly pa-
tients can have difficulty swallowing tablets, making the
liquid form a useful alternative. The difficulty with a liquid
form is that enalapril degrades in water. The ’482 and ’621
patents aim to remedy this and claim a liquid formulation
that “maintains about 95% w/w or greater of the initial en-
alapril amount at the end of a storage period of at least 12
months at about 5±3° C.” ’482 patent, col. 42 ll. 21–23.
Alkem Laboratories, Ltd. (“Alkem”) submitted an Ab-
breviated New Drug Application (“ANDA”). Azurity
brought suit claiming the ANDA infringed the ’482 and
’621 patents. The district court agreed that the ANDA in-
fringed, and that determination is not challenged on ap-
peal. However, the district court also found the ’482 and
’621 patents were invalid due to obviousness and insuffi-
cient written description. Azurity appeals.
D ISCUSSION
“Obviousness is a mixed question of fact and law.” No-
vartis AG v. Torrent Pharms. Ltd., 853 F.3d 1316, 1327
(Fed. Cir. 2017). The district court’s legal conclusion of ob-
viousness is subject to de novo review, while “subsidiary
factual findings are reviewed for substantial evidence.” Id.
Substantial evidence is “such relevant evidence as a
Case: 23-1540 Document: 35 Page: 2 Filed: 09/14/2023

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AZURITY PHARMACEUTICALS, INC. v.
ALKEM LABORATORIES LTD.
3
reasonable mind might accept as adequate to support a
conclusion.” Consol. Edison Co. v. NLRB, 305 U.S. 197, 229
(1938).
We see no legal error in the district court’s obviousness
determination and conclude that it was supported by sub-
stantial evidence. Because we affirm the district court’s ob-
viousness determination, we decline to reach the issue of
written description.
AFFIRMED
Case: 23-1540 Document: 35 Page: 3 Filed: 09/14/2023

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