By Andrew Williams —

Saying
"But I won't do it" is not sufficient to avoid infringement in a
Hatch-Waxman litigation, according to the Federal Circuit in the recently
decided Sunovion Pharmaceuticals, Inc. v.
Teva Pharmaceuticals USA, Inc.  The
ANDA applicant in that case was applying to market a generic version of Lunesta^®,
a chiral drug sold as a sleep medication.  The lower court had construed one of the claims to require "less
than 0.25%" of an unwanted chemical entity.  However, the ANDA applicant was seeking to
market a drug with "not more than 0.6%" of this chemical entity,
which as the Court pointed out, is between 0.0-0.6%.  Therefore, even though the ANDA applicant had
submitted a declaration to the District Court (but not the FDA) vowing that it
would only market its generic product with levels of this chemical entity at
0.3-0.6%, the Federal Circuit still found that the ANDA application had
infringed for purposes of 35 U.S.C. § 271(e)(2).  "What a generic applicant asks for and receives approval to market,
if within the scope of a valid claim, is an infringement."  As the Federal Circuit suggested, instead of
telling a Court that it would not infringe a patent should it get approval to
market it generic product, an ANDA applicant in such a case should instead
amend its ANDA application to avoid infringement.

As
background, Sunovion owns the rights in U.S. Patent No. 6,444,673 ("the '673
patent"), which claims the single-enantiomer drug eszopiclone.  For those readers not up on chiral chemistry,
chemical entities with, for example, a carbon atom and four different
substituent atoms can assume two different structures that look similar but are
not superimposable.  The classic example
used to illustrate this is your left and right hands.  Instead of being superimposable, they are
mirror images of each other.  For
chemical entities, the two different entities are called stereoisomers, and
each individual stereoisomer is referred to as an enantiomer.  One enantiomer is termed the dextrorotatory
or (S)-enantiomer, while the other is
termed the levorotatory or (R)-enantiomer.  In the case of the '673 patent, the
dextrorotatory entity is claimed, as shown in representative claim 1:

1.    6-(5-chloro-2-pyridyl)-5-[(4-methyl-1-piperazinyl)carbonyloxy]-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazine,
or a pharmaceutically acceptable salt thereof, in the form of its
dextrorotatory isomer and essentially free of its levorotatory isomer.

Lunestra^®
is, of course, the dextrorotatory isomer, and the FDA required it contain no
more than 0.3% of levorotatory isomer, referred to as (R)-zopiclone.

Dr.
Reddy's Laboratories, Ltd. and Dr. Reddy's Laboratories, Inc. (collectively "Dr.
Reddy") submitted an ANDA to market a generic version of Lunestra^®,
which included a Paragraph IV certification to the '673 patent.  In turn, Sunovion sued Dr. Reddy pursuant to
35 U.S.C. § 271(e)(2).  The District Court construed the claim term "essentially free" to mean "less
than 0.25% of [the] levorotatory isomer."  Dr. Reddy's initial ANDA application included the levels of the
levorotatory isomer to be "[n]ot less than 0.3% and [n]ot more than 1.0%."  The FDA required Dr. Reddy to tighten this
limit to not more than 0.3%.  Instead,
Dr. Reddy amended its application to recite not more than 0.6% of the
levorotatory isomer.  The Federal Circuit
opinion suggested that Dr. Reddy's generic product had not yet received
approval.  Nevertheless, as indicated
above, Dr. Reddy "certified" to the lower court that it would not
market any drug product that contained less than 0.3% of the levorotatory
isomer, even though the FDA had suggested that it would not allow approval of
such a limitation.  In addition, the
lower court accepted the fact that Dr. Reddy's internal manufacturing
guidelines resulted in a level of levorotatory isomer that was more than 0.3%.  Therefore, the lower court granted a summary
judgment motion of noninfringement.

Sunovion
first challenged the construction of the term "essentially free,"
which it thought should be defined as "largely but not wholly free"
of the levorotatory isomer.  This claim
term was not defined in the specification, but according to the Court it was
used more than once in the prosecution history to mean "less than 0.25%."  One of these times, the applicants had stated
that the disclosure of Example 1 was evidence of material that "consists
essentially of" the dextrorotatory isomer.  Of course, even though this phase does have the word "essentially"
in it, the phrase "consists essentially of" has a particularized
meaning in patent parlance.  It should,
therefore, not be evidence of what the applicants' thought to term "essentially"
meant, at least with regard to the levorotatory isomer.  However, the applicants also submitted a
declaration during prosecution in which it was stated that the "pure form"
of the dextrorotatory isomer "as described in Example 1" contained "lower
than 0.25%" of the unwanted stereoisomer.  This declaration was used in a subsequent interference as support for the
term "essentially free" to be equated with containing less than 0.25%
levorotatory isomer.  The Federal Circuit
found that the "applicants' repeated and consistent attribution of the
purity level of less than 0.25% levorotatory isomer to 'the invention' and the 'the
instant invention' thus gives meaning to the term 'essentially free.'"  Accordingly, the Court affirmed the lower
court's claim construction.

Sunovion,
nevertheless, also argued that even with the lower court's construction of this
claim term, Dr. Reddy also infringed.  As
indicated above, the Federal Circuit agreed, because Dr. Reddy was seeking
approval to market a generic version of the drug that could fall within the scope
of the asserted claims.  The Court was
not impressed with the internal manufacturing guidelines or the "certification"
made to the court below.  Instead, "the
ultimate infringement question is determined by traditional patent law
principles . . . ."  The Court
believed that allowing an ANDA applicant to avoid infringement based on "unconventional
and unenforceable 'guarantee[s]'" while seeking to market a product that
fell with the scope of asserted claims "would be incompatible" with
those principles.

Dr.
Reddy tried to rely on the Federal Circuit cases of Bayer AG v. Elan Pharmacetuical Research Corp., 212 F.3d 1241 (Fed.
Cir. 2000), and Glaxo, Inc. v. Novopharm,
Ltd., 110 F.3d 1562 (Fed. Cir. 1997).  However, in both of those cases, the Court had found that the ANDA
product described in the application fell outside the scope of the patents at
issue.  In fact, in Bayer, the NDA holder had based its infringement contention on a
particular biobatch received from the ANDA applicant, which when tested fell
within the scope of the claims.  However,
the Court in that case noted that the biobatch did not fall within the
specification of the ANDA application, and therefore was irrelevant for
purposes of infringement under § 271(e)(2).  The present case presents almost the converse issue — the ANDA applicant
is asserting that the product it will market will fall outside the scope of the
claim, but this is contrary to what the ANDA application teaches.  "[Dr.] Reddy's ANDA specification clearly
describes a product that meets the limitations of the asserted claims."  Correspondingly, the Federal Circuit reversed
the lower court's judgment of noninfringement.

Sunovion
Pharmaceuticals, Inc. v. Teva Pharmaceuticals USA, Inc. (Fed. Cir. 2013)
Panel:
Circuit Judges Lourie, Schall, and Reyna
Opinion
by Circuit Judge Lourie