Endo mainly prevails at CAFC in case related to painkiller opioid oxymorphone

The result of this Hatch-Waxman case was mainly a victory for the patent holder Endo:


The generic drug manufacturers argued generally that
the asserted patents’ claims were invalid or not infringed.
The district court rejected those arguments and found all
asserted claims of the ’122 and ’216 patents not invalid,
and all but two asserted claims infringed. Because there
is no reversible error in the district court’s findings, we
affirm.



Of details of the district court decision:


The district court concluded that the generic drug
manufacturers failed to show that the asserted claims of
the two patents are invalid. J.A. 128–29. Specifically, the
court found that the asserted claims of the two patents
are not invalid for obviousness; that the asserted claims
with the dissolution limitations are not invalid for lack of
written description; and that the asserted claims reciting
the multiple peaks limitations are not invalid for indefiniteness.
The court also found that Endo carried its
burden to show that defendants infringe or will infringe
all but two of the asserted claims of the ’122 and ’216
patents. J.A. 72–73. The court then issued a permanent
injunction against Actavis’s manufacture, use, offer to
sell, or sale of its generic version of OPANA®ER prior to
the expiration of the ’122 and ’216 patents. J.A. 182.



Of teaching away:


Amneal contends that the court erred by finding that
oxymorphone’s low bioavailability teaches away from
attempting a controlled release formulation. Overwhelming
evidence at trial, however, supports that factual
finding. Expert testimony showed that a skilled artisan
would not have been motivated to select oxymorphone for
use in a controlled release setting because of its “exceptionally
low bioavailability.” J.A. 98. As the district court
noted, the Oshlack reference also taught that “bioavailability
is a significant, even crucial, factor in evaluating a
drug’s suitability for placement in a controlled release
vehicle.” J.A. 92. The court also observed that “[t]he
notion that low-bioavailability drugs were considered
unsuitable for extended-release formulation is reinforced
by the fact that, until Endo’s development of OPANA®ER,
there were remarkably few such examples.” J.A. 94. For
example, the existence of another low-bioavailability
drug, oxybutynin—a non-opioid analgesic, unlike oxymorphone—which
had previously been developed into a
controlled release formulation, served to underscore “the
fact that low bioavailability drugs were remarkably rare
in controlled-release settings.” J.A. 95. Indeed, “its total
absence from the expert reports of both sides, impressed
on the court that low-bioavailability drugs were, at the
time of the invention, perceived as unsuited for development
into controlled release forms.” Id. Tellingly, Appellants’
own expert maintained the view that active
ingredients with poor bioavailability would not be good
candidates for controlled release dose forms. J.A. 2769.
Appellants contend that the low bioavailability of oxymorphone
could be addressed by increasing the dosage.
The district court did not err in rejecting that argument.
The court found, based on published research, that such
an approach “risk[ed] toxicity.”

(...)

Oxymorphone’s inclusion in Maloney’s and Oshlack’s
lists of candidate molecules does not alter this conclusion.
Those lists mention oxymorphone among a vast number of
other molecules, including drugs such as heroin, opium,
and fentanyl, so the district court doubted that the lists
would be taken seriously as indicating suitability for
controlled release treatment. J.A. 96–98. The court
noted, for example, that fentanyl was widely understood
as suitable only for transdermal, not oral, delivery. J.A.
96–97. Given that context, the district court reasonably
found that a skilled artisan would not have viewed oxymorphone
as suitable for a controlled release setting.
Moreover, neither Penwest S-1 nor Cleary discloses any
technical details, such as dosing interval or twelve-hour
efficacy, for achieving the claimed inventions. J.A. 3144–
45. Accordingly, a person of ordinary skill, upon reading
those references, would have been strongly discouraged
from using oxymorphone in a controlled release setting.
The district court did not clearly err in finding that the
references taught away from the claimed invention.


Of written description


The written description requirement provides that a
patentee’s application for a patent must “clearly allow
persons of ordinary skill in the art to recognize that [he]
invented what is claimed.” Ariad Pharm., Inc. v. Eli Lilly
& Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc)
(quoting Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1563
(Fed. Cir. 1991)). “[T]he test for sufficiency is whether the
disclosure of the application relied upon reasonably
conveys to those skilled in the art that the inventor had
possession of the claimed subject matter as of the filing
date.” Id.



Of injunction and irreparable harm:


Endo relatedly demonstrated, mainly through trial
testimony, that it had to lay off its sales force, which may
damage its reputation in the market segment and make
the company less attractive to potential new hires. The
court found that such irreparable harm cannot be adequately
addressed without an injunction.