Thursday, November 12, 2015

CAFC affirms D. Del. in Cubist case

In Cubist v. Hospira, appeals were made from
the United States District Court for the
District of Delaware in No. 1:12-cv-00367-GMS, Judge
Gregory M. Sleet; the CAFC affirmed D. Del.

Some background on the Cubist case:

Daptomycin was developed by Eli Lilly & Co. (“Lilly”).
The original patent to daptomycin expired in 2002. The
five patents at issue in this case are all follow-on patents
owned by Cubist. The first is U.S. Patent No. RE39,071
(“the ’071 patent”), which is a reissue of U.S. Patent No.
5,912,226 (“the ’226 patent”) and is directed to antibiotic
compounds, compositions, formulations, and methods of
treating bacterial infections. The next two are U.S.
Patent Nos. 6,852,689 and 6,468,967 (“the ’689 and ’967
patents”), which are entitled “Methods for Administration
of Antibiotics” and are directed to dosage regimens for
administering daptomycin. The final two are U.S. Patent
Nos. 8,058,238 and 8,129,342 (“the ’238 and ’342 patents”),
which are entitled “High Purity Lipopeptides” and
are directed to the purification of daptomycin compositions.
Cubist sells its daptomycin formulation under the
trade name Cubicin. In 2011, Hospira filed an Abbreviated
New Drug Application with the Food and Drug Administration
seeking approval to manufacture and sell an
equivalent daptomycin product prior to the expiration of
Cubist’s patents. Pursuant to procedures set forth in the
Hatch-Waxman Act, Cubist then filed an action in the
United States District Court for the District of Delaware,
alleging that Hospira had infringed all five of Cubist’s
patents. Hospira responded by challenging the validity of
the asserted claims of each of those patents. Two other
related actions brought by Cubist were subsequently
consolidated with the initial lawsuit.
Following a bench trial, the district court held some of
the asserted claims of four of Cubist’s patents invalid for
anticipation and all the asserted claims of those patents
invalid for obviousness. As for the fifth patent, the court
held the two asserted claims not invalid and ruled that
Hospira’s proposed products infringed those claims. Both
parties appeal from the portions of the judgment adverse
to them.

Bottom line

We affirm the judgment of the district court,
relying heavily on the factual findings made by the court
following the trial.

Of the "certificate of correction" issue

It turns out that the structural diagram of the compound
identified as Formula 3 and depicting daptomycin
was inaccurate in one respect. The structure in the
diagram contained 13 amino acids, including asparagine
(abbreviated “Asn”). While the diagram accurately identified
the amino acids and their location in the daptomycin
molecule, it mistakenly identified the stereoisomer of the
asparagine amino acid as the “L” stereoisomer of asparagine,
rather than the “D” stereoisomer.

At the time the application for the ’226 patent was
filed, and until well after that patent was issued, it was
universally believed that the asparagine amino acid in
daptomycin was the L-isomer of asparagine, as set forth
in the structural diagram. Years after the issuance of the
’226 patent and after the reissue application for the ’071
patent was filed, Lilly researchers discovered that daptomycin
actually contains the D-isomer of asparagine, not
the L-isomer.

In 2007, Cubist sought to correct the error by requesting
a certificate of correction from the Patent and Trademark
Office (“PTO”) pursuant to 35 U.S.C. § 255. Cubist
explained that the mistake in the patent as to the identity
of the stereoisomer of asparagine was “the result of the
mischaracterization of one of the A-21978C factors described
by Formula 3.” Specifically, Cubist explained,
“the patentees erred in describing one amino acid’s stereochemistry
as ‘L-Asn’ in the tail of the compound illustrated
in Formula 3, when the correct stereochemistry of
the disclosed and claimed amino acid is ‘D-Asn.’” Cubist
further explained that the true nature of the stereochemistry
of daptomycin was disclosed in a 2005 journal article
by Vivian Miao et al. The Miao article, Cubist stated,
“demonstrates that the A-21978C factors of Formula 3
inherently contain the ‘D-Asn’ in the tail portion illustrated
in Formula 3 when isolated from their native source,
not an ‘L-Asn.’”

The examiner concluded that it was appropriate to
use a certificate of correction to correct the error identified
by Cubist. Accordingly, the examiner issued the certificate,
correcting the diagram of Formula 3 in the specification
and four of the claims of the ’071 patent by
substituting “D-Asn” for “L-Asn” in the diagram.

Of the relevant law

On appeal, Hospira argues that the change in the ’071
patent made by way of the certificate of correction was not
a change “of minor character,” as provided for in section
255, because the change broadened the scope of the asserted
claims. See Superior Fireplace Co. v. Majestic
Prods. Co., 270 F.3d 1358, 1375 (Fed. Cir. 2001) (“A
mistake that, if corrected, would broaden the scope of a
claim must thus be viewed as highly important and thus
cannot be a mistake of ‘minor character.’”). In Hospira’s
view, because the change from L-Asn to D-Asn in the
structural diagram broadened the scope of the claims to
read on daptomycin rather than the L-Asn variant of
daptomycin, the certificate of correction was invalid.
Once the PTO has issued a certificate of correction, a
court may invalidate the certificate only upon a showing
of clear and convincing evidence that it was improperly
issued. Superior Fireplace Co., 270 F.3d at 1367. In this
case, no such showing has been made.


As this court has noted, a chemical structure is
“simply a means of describing a compound; it is not the
invention itself.” Regents of Univ. of N.M. v. Knight, 321
F.3d 1111, 1122 (Fed. Cir. 2003).

One notes that claim 1 of US '226 incorporated the
formula as a claim element:

1. A compound of the formula ##STR12## in which R is C.sub.5 -C.sub.14 -alkanoyl;
R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are hydrogen; or
a pharmaceutically acceptable salt thereof.

The problem is that "what was claimed" was not "what was possessed."


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