On Dec 22, 2017, District court of Delaware held that a patent
related to Estradiol (Minivelle®) ER film is valid but not
infringed because of prosecution history estoppel.
Noven is the holder of New Drug Application
("NDA") No. 203752, for the manufacture and sale of an estradiol
transdermal delivery system (Minivelle®),
with dosages of 0.025 mg/day, 0.0375 mg/day, 0.05 mg/day, 0.075 mg/day and 0.1
mg/day. Minivelle® is indicated for treatment of moderate to severe vasomotor
symptoms (also known as "hot flashes") due to menopause and for the
prevention of post-menopausal osteoporosis. On March 20, 2015, Plaintiff Noven
Pharmaceuticals, Inc. ("Noven" or "Plaintiff') filed suit
against Defendant Actavis Laboratories UT, Inc. ("Actavis" or
"Defendant") alleging infringement of U.S. Patent No. 8,231,906 (the "'906 patent"), which is
directed to a transdermal product for the delivery of the hormone estradiol.
The Court held a claim construction hearing on May 3, 2016 and issued a claim
construction opinion on July 5, 2016. The Court conducted a three-day bench
trial in January and February of 2017 and heard closing arguments on May 8,
2017. At trial and in its post-trial briefing, Noven claimed that Actavis
infringed the asserted claims of the '906 patent literally and under the
doctrine of equivalents. Actavis, in turn, claimed that prosecution history
estoppel barred Noven from asserting infringement under the doctrine of
equivalents and that the asserted claims of the '906 patent were invalid as
obvious.
Infringement under
DOE & prosecution history estoppel:
Noven asserted that Actavis's proposed generic product
and/or manufacturing process infringe claims 1-14 of the '906 patent. Claim 1
reads:
1. A monolithic
transdermal drug delivery system for estradiol, comprising a single polymer
matrix layer defining an active surface area and comprising a polymer matrix
comprising estradiol as the only drug, wherein the polymer matrix layer has a coat weight selected from the group
consisting of 12.5 mg/cm2 and 15 mg/cm2 , includes greater than 0.156
mg/cm2 estradiol, and achieves an estradiol flux that is greater than 0.01
mg/cm2 /day, based on the active surface area.
On May 29, 2012 during prosecution, claim 1 did not contain
a quantitative coat weight limitation. On May 29, 2012, the PTO issued a Final
Office Action, rejecting certain claims under 35 U.S.C. § 103 over certain prior
arts such as Kanios, Nuwayser & Rovati. With respect to the rejections,
the Examiner stated that although Rovati "does not teach that the system
achieves an estradiol flux that is greater than 0.01 mg/cm2 /day,"
"[i]t would have been obvious to one of ordinary skill in the art at the
time that the invention was made to utilize the matrix taught by Kanios II in
the monolithic patch of Rovati ... to achieve the instantly claimed estradiol
flux." On May 30, 2012, in response to the May 29, 2012 Final Office
Action, Applicant amended claim 1 & argued that amended claim 1 was
patentable over Rovati in view of Kanios II because both prior art
references did not "teach or suggest a polymer matrix coat weight as recited in the instant claims." Applicant
also argued that "Rovati does not recognize any criticality of the coat
weight of the polymer matrix" and that "Rovati's example appears to
have a coat weight of about 9.8 mg/cm2 which
is significantly lower than the 12.5 or 15 mg/cm2 recited in the claims."
Actavis contended that prosecution history estoppel bars
Noven from asserting infringement of claim 1 under the doctrine of equivalents.
Actavis's arguments focused on the "coat weight" limitation of
claim 1. In Actavis's view, the Applicant "added the 'coat weight'
limitation to distinguish the claims from" Rovati. Actavis further
contended that Noven cannot establish "the narrow tangential relation
exception to prosecution history estoppel," "[b]ecause both the
reason for the amendment and the asserted equivalent relate to [the coat weight
of the polymer matrix layer]." Noven asserted that the "coat
weight" amendment "was not made for reasons of patentability or to
narrow the claims in view of the prior art" but, instead, was made
"to claim two specific embodiments." Moreover, even if estoppel would
presumptively apply, Noven contends that the coat weight amendment "was
only tangentially related to the equivalent in question" because "[t]he
amendment rewrote the limitation into the independent claim."
Court said that the '906 patent's prosecution history
demonstrates that the Applicant added the coat weight limitation to overcome
a § 103 rejection based on Rovati in view of Kanios II. For example, in its
response to the PTO's rejection, the Applicant stated that "Rovati does
not recognize any criticality of the coat weight of the polymer matrix"
and that "Rovati' s example appears to have a coat weight of about 9 .8
mg/cm2 [,] which is significantly lower than the 12.5 or 15 mg/cm2 recited in
the claims." The Applicant further stated that Rovati "does not teach
or suggest a polymer matrix coat weight as recited in the instant claims"
and that "Kanios II does not provide any teachings regarding the coat
weight of its polymer matrix." From these statements (and the entirety of
the prosecution history), the Court concludes that the Applicant used the coat
weight amendment to distinguish the amended claim over Rovati, making the coat
weight amendment substantially related to patentability.
For the reasons explained above, the Court concluded that
the coat weight amendment was a narrowing amendment made to distinguish the
claim over prior art and further concluded that the reason for the
amendment was not tangentially related to the equivalent in question.
Consequently, prosecution history estoppel bars Noven from asserting
infringement of the coat weight limitation under the doctrine of equivalents.
Invalidity:
Actavis argued that the asserted claims are obvious over the
prior art because: (1) a POSA would have been motivated to make a smaller
estradiol transdermal delivery system; (2) the specific size reduction in
making a smaller transdermal estradiol delivery system would have been a design
choice; (3) a POSA attempting to modify Vivelle-Dot® would have been motivated
to keep the polymer matrix weight ofVivelle-Dot® the same and would, therefore,
arrive at the claimed coat weight limitation; (4) a POSA attempting to modify
Vivelle-Dot® would have been motivated to use the same amount of estradiol as
Vivelle-Dot®, thereby increasing the amount of estradiol per unit area; and (5)
a POSA attempting to modify VivelleDot® would have been motivated to increase
flux.
Court after hearing both the parties held that the Court is
not persuaded that a POSA would have been motivated by the prior art to develop
a transdermal estradiol system smaller than Vivelle-Dot®. Although Actavis
correctly observed that its cited "prior art [references] ... disclose[]
that patients preferred smaller estradiol transdermal drug delivery
systems," none of the references indicates that patients preferred a
transdermal estradiol patch smaller than Vive/le-Dot® Further the Court
agrees with Noven that "a POSA
would not have had a reasonable expectation of success in implementing any
chosen size reduction" because a "POSA would have had to test
numerous combinations ... to determine if flux could be increased enough"
to allow for that size reduction. Additionally, although certain techniques
were known to be beneficial in increasing flux, a POSA would recognize that those
same techniques could also deleteriously impact other aspects of the drug's
profile. Accordingly, the Court concluded that the specific size reduction
in designing a smaller patch would not have been "an obvious design
choice." Given this conclusion and the evidence cited above, Actavis has
failed to prove that the claimed size limitations would have been obvious to a
POSA in July 2008.
Accordingly, again, Actavis has failed to prove that the
polymer matrix weight limitation, estradiol limitation, flux limitation would
have been obvious to a POSA at the priority date of the '906 patent. Also there
is a nexus between Minivelle®'s commercial success and the invention claimed in
the '906 patent. Minivelle®'s size - a feature claimed by the '906 patent - has
been a central theme of promotion since Minivelle®' s launch and is crucial to
its success. Accordingly, Noven has proven a causal nexus. The secondary
consideration of commercial success further demonstrates the nonobviousness of
the asserted claims of the '906 patent.
CONCLUSION:
Pursuant to Federal Rule of Civil Procedure 52(a), and
having considered the entire record with respect to prosecution history
estoppel and invalidity, the Court concluded that:
(1) Prosecution history estoppel bars Noven from asserting
infringement of the coat weight limitation of the '906 patent under the
doctrine of equivalents; and
(2) Actavis has failed to prove, by clear and convincing
evidence, that the asserted claims of the '906 patent are invalid as obvious.
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