  United States Court of Appeals
      for the Federal Circuit
                ______________________

                 SANOFI-AVENTIS,
                    Appellant,

                           v.

                    PFIZER INC.,
                       Appellee.
                ______________________

                      2012-1345
                ______________________

    Appeal from the United States Patent and Trademark
Office, Board of Patent Appeals and Interferences in No.
105,757.
                 ______________________

              Decided: November 5, 2013
               ______________________

   Thomas J. Vetter, Lucas & Mercanti, LLP, of New
York, New York, argued for appellant.

   Z. Ying Li, Ropes & Gray, LLP, of New York, New
York, argued for appellee. With her on the brief was
James F. Haley, Jr.
                ______________________
2                             SANOFI-AVENTIS   v. PFIZER INC.
Before NEWMAN, and LOURIE, Circuit Judges, and DAVIS,
                  District Judge. 1
NEWMAN, Circuit Judge.
   Sanofi-Aventis (“Sanofi”) appeals the decision of the
United States Patent and Trademark Office (“PTO”)
Board of Patent Appeals and Interferences (“the Board”), 2
awarding priority of invention to Pfizer Inc. (“Pfizer”)
based on the following interference count:
    Count 3. The isolated protein of 6,268,480 claim
    4;
                            OR
    The isolated polynucleotide of 5,710,023 claim 1,
    selection (b) (an isolated polynucleotide compris-
    ing a nucleotide sequence of SEQ ID NO:3 from
    nucleotide 103 to nucleotide 1242).
Nucleotides 103 to 1242 constitute the protein-encoding
portion of the complementary deoxyribonucleic acid
(“cDNA”) for the human interleukin-13 receptor binding
chain (“IL-13bc”).
    The parties disagree as to the dispositive question in
the interference. As summarized by Pfizer, the question
is “who first had in hand the actual isolated DNA of the
count and appreciated its IL-13bc function.” Pfizer Br. 1.
As summarized by Sanofi, the question is “the date each
party first knew the complete sequence” of nucleotides


    1    The Honorable Leonard Davis, Chief Judge, Unit-
ed States District Court for the Eastern District of Texas,
sitting by designation.
    2   Sanofi-Aventis v. Pfizer Inc., Patent Interference
No. 105,757 (Bd. Pat. App. & Int. Jan. 5, 2012). Pfizer
was substituted for Genetics Institute as the real party in
interest.
SANOFI-AVENTIS   v. PFIZER INC.                            3
103 to 1242. Sanofi Br. 4. The Board agreed with Pfizer
that possession and appreciation of the actual isolated
DNA is the dispositive question for priority of conception
for an interference count directed to the isolated DNA,
and on that basis awarded priority to Pfizer.
                         BACKGROUND
    IL-13 is a regulatory molecule called a cytokine. Cy-
tokines function by interacting with cytokine receptors
located on target cells. The subject of this patent interfer-
ence is a DNA polynucleotide that encodes the protein
binding chain of the IL-13 receptor. Both Sanofi and
Pfizer were conducting research in this field of scientific
endeavor, for therapeutic and diagnostic purposes, and
both Sanofi and Pfizer discovered and filed patent appli-
cations directed to the polynucleotide encoding the rele-
vant IL-13 binding chain.
    In accordance with the applicable law, 3 the patent is
awarded to the first party to conceive and reduce to
practice the invention represented by the interference
count. See Cooper v. Goldfarb, 154 F.3d 1321, 1327 (Fed.
Cir. 1998) (“[P]riority of invention goes to the first party
to reduce an invention to practice unless the other party
can show that it was the first to conceive of the invention
and that it exercised reasonable diligence in later reduc-
ing that invention to practice.”). This law is implemented
in accordance with rules and precedent, administered by
the PTO Board (“Board”). On appeal to the Federal
Circuit, we review the Board’s rulings of law for correct-
ness, and factual findings for support by substantial
evidence. See Dawson v. Dawson, 710 F.3d 1347, 1353
(Fed. Cir. 2013) (“The issue of conception turns in large


    3   The America Invents Act (“AIA”), Pub. L. No. 112-
29, obviated patent interferences. Pursuant to AIA
§3(n)(2)(A), this interference remains governed by the
prior laws.
4                             SANOFI-AVENTIS   v. PFIZER INC.
part on the facts, and we review the Board’s many factual
findings in this case for substantial evidence.”).
    Sanofi was awarded the benefit of its December 6,
1995 priority date. Pfizer’s filing date is March 1, 1996;
Pfizer thus bore the burden of proving a date of concep-
tion earlier than the Sanofi benefit date. Pfizer presented
documentary and testimonial evidence that it had isolated
and identified the desired cDNA before the Sanofi benefit
date. However, due to sequencing errors, Pfizer did not
then have a completely accurate analysis of the entire
nucleotide sequence. The Board found that Pfizer had
“the claimed polynucleotide in hand with some additional
identifying information including at least a partial se-
quence,” and ruled that Pfizer “established conception and
actual reduction to practice of a polynucleotide within the
scope of count 3” before the Sanofi benefit date. Bd. Op.
at 17.
    On appeal, Sanofi argues that Pfizer cannot be credit-
ed with conception because although Pfizer’s sequence
analysis before the Sanofi date was correct as to 1135 of
the 1143 nucleotides, the analysis was in error as to eight
nucleotides. The Board found that Pfizer corrected this
analysis by February 7, 1996. The Pfizer patent applica-
tion filed on March 1, 1996 contained the correct analysis.
Sanofi argues that conception of the claimed cDNA could
not be established for priority purposes until the fully
correct nucleotide sequence was determined, because the
interference count is directed to the isolated polynucleo-
tide. Sanofi argues that until Pfizer had correctly ana-
lyzed the polynucleotide, neither conception nor reduction
to practice could occur. Sanofi states that Federal Circuit
precedent requires the full and correct nucleotide se-
quence to establish conception, because reduction to
practice, whether actual or constructive, requires the full
and correct nucleotide sequence.
SANOFI-AVENTIS   v. PFIZER INC.                           5
    The Board did not share Sanofi’s view of law and
precedent. The Board held that Pfizer had established
conception of the subject matter of the count when it
selected, isolated, and obtained the desired IL-13bc full-
length polynucleotide and verified that it was the desired
product, regardless of whether the fully correct sequenc-
ing of the polynucleotide was complete. Sanofi argues on
this appeal that the Board erred in law.
                          DISCUSSION
    As junior party with the burden of proof, Pfizer pre-
sented evidence of its research with murine and human
IL-13 starting in early 1995. The Board found that co-
inventor Lori Fitz performed binding assays with com-
mercially supplied human IL-13 in conjunction with
recombinant murine IL-13bc protein fused to an antibody
fragment known as the Fc domain. Ms. Fitz verified that
the murine IL-13bc protein bound human IL-13 and that
the interaction was specific, conducting experiments that
showed that the protein could be blocked with excess
murine IL-13bc fusion protein or with anti-human IL-13
antibody.
    After isolating the murine IL-13bc, by October 16,
1995 Pfizer scientists isolated the human IL-13bc, called
clone 11, from a human cDNA library. Co-inventor Mat-
thew Whitters testified that he aligned the sequence of
clone 11 with the respective sequences of the murine IL-
13bc, and summarized his conclusions:
   [G]iven the size of the clone 11 insert (it corre-
   sponded to the mouse A25 full-length clone [i.e.,
   murine IL-13bc]), the significant sequence identi-
   ty and similarity between the amino acid se-
   quence deduced from the nucleotide of the 5' end
   of the cDNA of the clone 11 insert and the mouse
   A25 protein, the identification of the 5' end of the
   cDNA and the confirmation that it encoded the N-
   terminus of the protein and the fact that the
6                              SANOFI-AVENTIS   v. PFIZER INC.
    cDNA contained the 3' end of the coding sequence,
    on October 25, 1995, I was highly confident, and
    virtually positive, that the clone 11 insert con-
    tained the full-length nucleic acid coding sequence
    for the human homolog of the mouse A25 protein.
Whitters Decl. 6, Feb. 25, 2011. Mr. Whitters also testi-
fied that on November 15, 1995 he was provided with a
computer printout of the nucleotide sequence of clone 11,
and the next day he was provided with the deduced amino
acid sequence encoded by that clone. He testified that the
nucleotide sequence and amino acid sequence were
checked for errors by comparison with the sequences for
additional human IL-13bc products that Pfizer had isolat-
ed from its cDNA library.
    Whitters testified that for the polynucleotide sequence
eight possible errors were found out of 1143 nucleotides,
and that the encoded amino acid sequence was correct for
379 out of 380 residues. He testified that correction of
these sequences was completed by December 12, 1995 and
confirmed by February 7, 1996.
    It was not disputed that clone 11 was the desired
product. Pfizer argued that its initial sequence was 99.3%
accurate, and that the sequencing errors were routinely
detected and corrected. The Board held that Pfizer had
established conception and reduction to practice before
the Sanofi benefit date.
    Sanofi argues that as a matter of law Pfizer did not
have a complete conception until Pfizer had the full
correct nucleotide sequence, citing Federal Circuit prece-
dent including Amgen Inc. v Chugai Pharmaceutical Co.,
927 F.2d 1200 (Fed. Cir. 1991). Amgen does not support
Sanofi’s position. The court in Amgen held that when “an
inventor is unable to envision the detailed constitution of
a gene” there may nonetheless be conception and reduc-
tion to practice of the gene when the inventor is in posses-
sion of the gene and a method for its preparation, i.e.
SANOFI-AVENTIS   v. PFIZER INC.                           7
“after the gene has been isolated,” accompanied by
knowledge of “other characteristics sufficient to distin-
guish it from other genes.” Amgen, 927 F.2d at 1206. The
Pfizer activity meets these criteria.
     Sanofi argues that Fiers v. Revel, 984 F.2d 1164 (Fed.
Cir. 1993) established a per se rule that conception of an
isolated DNA requires the full and correct nucleotide
sequence, and that this court limited Fiers to the filing
date of his application that described the complete nucleo-
tide sequence, and no earlier conception date. Sanofi
states that this court recognized that “conception of DNA,
like conception of any chemical substance, requires a
definition of that substance other than by its functional
utility” and that “[c]onception of a substance claimed per
se without reference to a process requires conception of its
structure, name, formula, or definitive chemical or physi-
cal properties.” Sanofi Br. 17-18, quoting Fiers, 984 F.2d
at 1169. Sanofi states that in Burroughs Wellcome Co. v.
Barr Laboratories, Inc., 40 F.3d 1223, 1229 (Fed. Cir.
1994) this court clarified that Fiers requires knowledge of
the complete nucleotide sequence as a condition of concep-
tion. Sanofi argues that Pfizer did not have a “definite
and permanent idea” of the complete and operative inven-
tion, as required by Hybritech Inc. v. Monoclonal Antibod-
ies, Inc., 802 F.2d 1367, 1376 (Fed. Cir. 1986).
     The Board held that Pfizer met the requirements of
precedent. The Board found that Pfizer had isolated clone
11 and appreciated that it encoded the full-length human
IL-13bc, had identified clone 11’s structural characteris-
tics, and had correctly analyzed over 99% of the nucleo-
tide sequence. The Board found that the inventors had
obtained the operative DNA and had described the meth-
od for obtaining it. It is not disputed that the Pfizer
scientists had isolated and obtained the IL-13bc DNA; the
issue is whether conception is negated because the nucle-
otide sequence was not corrected until after the Sanofi
benefit date of December 6, 1995.
8                             SANOFI-AVENTIS   v. PFIZER INC.
     The Board distinguished Fiers and Amgen as holding
that conception and reduction to practice did not occur
until the gene was isolated, for in those cases neither
structure nor definitive properties had been established
for the isolated gene. Bd. Op. at 16. Burroughs Wellcome
did not change these requirements, in holding that con-
ception requires that the claimed DNA is possessed as a
physical embodiment. Knowledge of the specific nucleo-
tide sequence was not required in Burroughs Wellcome.
    The Board elaborated that in this precedent the issue
was not identification of the operative DNA by full nucleo-
tide analysis, but isolation of the operative DNA and
identification by distinguishing properties of the isolate.
Amgen, 927 F.2d at 1206; Fiers, 984 F.2d at 1169. Amgen
and Fiers did not hold, as Sanofi asserts, that conception
requires the complete and correct sequencing of the
isolated DNA; the court instead referred to “whatever
characteristics sufficiently distinguish it.” Amgen, 927
F.2d at 1206. The Board was not persuaded by Sanofi’s
argument that since the interference count is in terms of
the nucleotide structure, Pfizer could not be credited with
conception of the IL-13bc product until it knew the com-
plete correct nucleotide sequence. Thus the Board held
that Pfizer had achieved conception and reduction to
practice before the Sanofi benefit date.
     Precedent illustrates a variety of circumstances in
which this requirement was met although the complete
nucleotide sequence was not known. In Enzo Biochem,
Inc. v. Gen-Probe Inc., 323 F.3d 956 (Fed. Cir. 2002) this
court upheld claims for certain DNA probes that were
made available by deposit in a public depository, as
provided by the Rules and PTO practice, although the
nucleotide sequence had not been determined. In Univer-
sity of New Mexico v. Knight, 321 F.3d 1111, 1122 (Fed.
Cir. 2003), the court explained that “a chemical structure
is simply a means of describing a compound; it is not the
invention itself.” The court stated in In re Wallach, 378
SANOFI-AVENTIS   v. PFIZER INC.                             9
F.3d 1330, 1333 (Fed. Cir. 2004) that when a protein was
described by a partial amino acid sequence in addition to
other characteristics sufficient to identify it, the inventors
were in possession of the protein.
    We conclude that the Board correctly based concep-
tion and reduction to practice on the possession of the
isolated DNA segment that was shown to have the desired
properties. When the subject matter is a DNA segment,
conception requires possession and appreciation of the
DNA segment that is claimed. See Invitrogen Corp. v.
Clontech Labs., Inc., 429 F.3d 1052, 1063-64 (Fed. Cir.
2005) (“[C]onception requires that the inventor appreciate
that which he has invented. . . . The priority determina-
tion requires evidence that the inventor actually first
made the invention, and that he understood his creation
to have the features that comprise the inventive subject
matter at bar.”). The Board found that Pfizer had suc-
cessfully searched for and isolated the IL-13bc DNA
segment, and possessed and appreciated the isolated IL-
13bc DNA before the Sanofi benefit date.
    Discussing the consequences of Pfizer’s flawed se-
quence analysis that was corrected after the Sanofi priori-
ty date, the Board stated that “[f]or proteins and
polynucleotide species, a sequence is the gold standard for
identifying species with precision . . . . It does not, how-
ever, thereby follow that a sequence is the only way to
identify the composition precisely.” Bd. Op. at 15. Upon
selecting, isolating and characterizing clone 11 Pfizer was
“able to define [the IL-13bc] so as to distinguish it from
other materials, and to define how to obtain it.” Amgen,
927 F.2d at 1206. The Board’s findings are supported by
substantial evidence.
    On these findings, the Board held that Pfizer had con-
ceived and reduced to practice the isolated polynucleotide
of Count 3 before the Sanofi benefit date. We conclude
10                          SANOFI-AVENTIS   v. PFIZER INC.
that the Board applied the correct law.   The award of
priority to Pfizer is affirmed.
                     AFFIRMED
