PTAB claim construction reversed in KAKEN PHARMACEUTICAL CO case

The case is about U.S. Patent No. 7,214,506 which describes and claims methods
for topically treating fungal infections in human nails.
The Patent Trial and Appeal Board of the Patent and
Trademark Office ultimately determined that all claims of
the ’506 patent are unpatentable for obviousness. Acrux
DDS Pty. Ltd. v. Kaken Pharm. Co., Ltd., No. IPR2017-
00190, 2018 WL 2761408 (P.T.A.B. June 6, 2018).

PTAB's decision did NOT stand.


The outcome was that the Board's construction was reversed, the decision vacated, and the case remanded:


The Director of the Patent and Trademark Office, who intervened after Acrux withdrew, defends
the Board’s decision. We agree with Kaken on its principal
contention—that the Board erred in its claim construction
of one claim limitation. Because the Board’s obviousness
analysis materially relied on its erroneous claim construction,
we cannot affirm the Board’s unpatentability determination. We reverse the claim construction, vacate the
Board’s decision, and remand the matter to the Board.



The issue:


Kaken challenges the Board’s construction of “treating
a subject having onychomycosis.” According to Kaken, the
Board’s construction ignores the ’506 patent’s core innovation—a topical
treatment that can easily penetrate the
tough keratin in the nail plate. Kaken asks us to reverse
the claim construction and either to reverse the obviousness determination
or to vacate it and remand for application of the proper construction.



The CAFC noted:


Prosecution history plays this role in applying the
broadest-reasonable-interpretation standard. See Microsoft Corp. v. Proxyconn, Inc., 789 F.3d 1292, 1298
(Fed. Cir. 2015), overruled on other grounds by Aqua
Prods., Inc. v. Matal, 872 F.3d 1290 (Fed. Cir. 2017)
(en banc). In this case, Kaken’s statements during prosecution, followed by the examiner’s statements, make clear
the limits on a reasonable understanding of what Kaken
was claiming.

(...)

The examiner credited Kaken’s explanation and withdrew the rejection. In allowing the claims, the examiner
stated, under the heading “Examiner’s Reasons for Allowance,” that “unexpectedly and in contrast to previously
evaluated compositions/methods, the instantly claimed
method cures the onychomycosis because the medicament
upon direct administration to the nail, penetrates through
the nail plate and eradicates the infection at the site.” Notice of Allowability dated Dec. 26, 2006, at 5, in Appl. No.
10/685,266 (emphasis added); J.A. 1608. The examiner
also suggested that Kaken cancel claim 18 and make claim
19 independent, which Kaken did, and the resulting claims
19 and 20 became claims 1 and 2 of the issued ’506 patent.
Compare Notice of Allowability dated Dec. 26, 2006, at 3–4
with ’506 patent, col. 17, line 34 through col. 18, line 32.
This exchange would leave a skilled artisan with no
reasonable uncertainty about the scope of the claim language in the respect at issue here. Kaken is bound by its
arguments made to convince the examiner that claims 1
and 2 are patentable. See Standard Oil, 774 F.2d at 452.
Thus, Kaken’s unambiguous statement that onychomycosis affects the nail plate, and the examiner’s concomitant
action based on this statement, make clear that “treating
onychomycosis” requires penetrating the nail plate to treat
an infection inside the nail plate or in the nail bed under
it.2



Note also



The foregoing determinations are infected by the erroneous claim construction.
In this court, the Director has
sought to support the Board’s factual findings with little or
no reliance on the claim construction we have held to be
erroneous. But that effort is more a reconstruction of the
Board’s analysis than a description of the Board’s actual
reasoning. We conclude that the appropriate course in this
case, as in so many others involving a reversal of a Board
claim construction, is to vacate the Board’s decision and remand the matter.
See, e.g., Arista Networks, Inc. v. Cisco
Sys., Inc., 908 F.3d 792, 798 (Fed. Cir. 2018); Dell Inc. v.
Acceleron, LLC, 818 F.3d 1293, 1300 (Fed. Cir. 2016).