Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-cand-3_05-cv-03955/USCOURTS-cand-3_05-cv-03955-7/pdf.json

Nature of Suit Code: 830
Nature of Suit: Patent
Cause of Action: 35:271 Patent Infringement

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United States District Court

For the Northern District of California

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UNITED STATES DISTRICT COURT

NORTHERN DISTRICT OF CALIFORNIA

THE REGENTS OF THE UNIVERSITY OF

CALIFORNIA, ABBOTT MOLECULAR INC., and

ABBOTT LABORATORIES INC.,

Plaintiffs,

v.

DAKOCYTOMATION CALIFORNIA, INC.,

Defendant. 

No. C 05-03955 MHP

MEMORANDUM & ORDER

Re: Motion for Preliminary

Injunction

Plaintiffs The Regents of the University of California (“UC Regents”), Abbott Molecular

Inc., and Abbott Laboratories Inc. (collectively, “Abbott”) brought this patent infringement action

against defendant DakoCytomation California, Inc. (“Dako”), alleging infringement of two United

States patents related to in situ DNA hybridization. Now before the court is plaintiffs’ motion for a

preliminary injunction prohibiting defendant from manufacturing or selling its HER2 FISH

pharmDxTM kit (“Dako kit” or “accused kit”) in the United States. Having considered the parties’

arguments and submissions, and for the reasons set forth below, the court enters the following

memorandum and order.

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BACKGROUND1

I. The Parties

Both Dako and Abbott manufacture diagnostic kits which measure the frequency of a

particular gene—the “HER2” gene—associated with an aggressive form of breast cancer. 

Declaration of Edward Michael in Support of Plaintiffs’ Motion for Preliminary Injunction

(“Michael Dec.”) ¶ 15; Declaration of Dennis Chernoweth in Support of Defendant’s Opposition to

Plaintiffs’ Motion for Preliminary Injunction (“Chernoweth Dec.”) ¶ 10. Approximately 25 percent

of breast cancer patients have additional copies of the HER2 gene in their cancerous cells. 

Chernoweth Dec. ¶¶ 5–6. The HER2 protein, which is encoded by the HER2 gene, makes the cancer

cells resistant to traditional forms of cancer treatment. Michael Dec. ¶ 12. A drug called Herceptin

is effective in mitigating the effects of the excess HER2 genes, but is expensive to administer. Id.

¶¶ 12, 14. The kits offered by Abbott and Dako identify the presence of excess HER2 genes in the

cancerous cells, which assists in deciding if treatment with Herceptin is needed.

Abbott is the current market leader for “genomic” tests that directly detect excess copies of

the HER2 gene. The Abbott PathVysion Test was administered to 42 percent of breast cancer

patients in 2004. Michael Dec. ¶ 26. The accused Dako kit is not currently in widespread use in the

United States. As of the filing date for Abbott’s motion, Dako had sold only 25 kits to customers in

North and South America, for a total of less than $50,000 in gross revenue. Chernoweth Dec. ¶¶

18–19. Dako is, however, also the manufacturer of an older diagnostic kit that detects excess HER2

protein, rather than directly detecting excess copies of the HER2 gene. Id. ¶ 9. Dako’s older kit

currently remains the most commonly used initial test for determining the need for treatment with

Herceptin. Id. ¶ 9. The older kit, however, fails to yield reliable results in 9 to 15 percent of its

applications. Id. ¶ 10. 

The parties disagree as to which company has greater power in the current market. Dako

argues that Abbott is in a position of greater power, as a result of its overall size—many times larger

than Dako—and the existing market for the PathVysion test. Abbott, in response, notes that Dako’s

sales force for HER2 kits in the United States is larger than Abbott’s, and argues that Dako will be

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able to make use of its existing base of customers for the older kit as leverage in promoting the

accused kit.

II. The Asserted Patents

Abbott holds the two patents at issue in this lawsuit, U.S. Patent No. 5,447,841 (the “‘841

patent”) and U.S. Patent No. 6,596,479 (the “‘479 patent”). The two asserted patents have identical

specifications but were issued almost eight years apart and have different claims. Both patents relate

generally to the identification of target genes in a tissue sample through DNA hybridization. In

DNA hybridization, sections of nucleic acid that are labeled, usually with a fluorescent dye

(“hybridization probes”), are bonded to complementary “target” regions of chromosomal

DNA—such as the gene encoding the HER2 protein. See, e.g., ‘841 patent at cols. 2–3. The

fluorescent label provides visual confirmation of the presence of the target gene. Id.

The basic technology involved in DNA hybridization predates the asserted patents. The

inventions described in the asserted patents improve upon the prior art hybridization process by

increasing its accuracy in two ways. First, in order to guarantee that a sufficient number of

hybridization probes will bond to the target region, the claimed inventions use a “heterogeneous

mixture of labeled unique sequence nucleic acid fragments” that “results in a substantially uniform

distribution of fragments hybridized to the chromosomal DNA.” Id. at 4:7–9.

Second, the claimed inventions include countermeasures that prevent hybridization probes

from bonding to regions of the chromosomal DNA outside of the target region. Of particular

concern are so-called “repeat” or “repetitive” sequences of DNA which occur throughout the

chromosomes but do not actually encode proteins. When these repeat sequences are similar in

structure to parts of the target regions, hybridization probes designed to attach to those parts of the

target region may instead hybridize at many undesired locations. The invention of the ‘841 patent

deals with repeat regions by using unlabeled hybridization probes (“blocking nucleic acid”) to bond

to the repeat sequences, which in turn prevents labeled probes from bonding to any repeat sequences

in the chromosomal DNA. See ‘841 patent at 17:9–12 (claiming “blocking nucleic acid that

comprises fragments which are substantially complementary to repetitive segments in the labeled

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nucleic acid”).2 The invention of the ‘479 patent deals with repetitive sequences by employing

labeled hybridization probes that are “unique”—not complementary to any repeat sequences. See

‘479 patent at 16:9–10 (claiming a “heterogeneous mixture of labeled unique sequence nucleic acid

fragments”) (emphasis added). These countermeasures constitute the key advances in the asserted

patents.

III. The Accused Kit

DNA hybridization may be performed on genetic material residing in various forms of tissue. 

For example, hybridization can be performed on DNA located within whole cells. The cells may be

processed prior to hybridization in order to permit the DNA probes to access the genetic material

contained in the nucleus. See ‘841 patent at 11:24–12:2.

Dako’s accused HER2 kit does not operate on whole cells. Instead, the accused kit operates

on “histologic” samples of cancerous breast tissue that have been fixed using a chemical called

formalin, and then thinly sliced for observation under a microscope. Declaration of Andreas

Schønau in Support of Defendant’s Opposition to Plaintiffs’ Motion for Preliminary Injunction

(“Schønau Dec.”) ¶ 9. The thickness of the slices is two- to three-times less than the diameter of a

typical cell nucleus. Declaration of Robert Singer in Support of Defendant’s Opposition to

Plaintiffs’ Motion for Preliminary Injunction (“Singer Dec.”) ¶ 10. As a result, most of the nuclei in

a histologic tissue sample will be partial slices of a complete nucleus. Id. During the majority of a

cell’s life cycle—“interphase,” or the period between cell divisions—the cell’s DNA is distributed

throughout the nucleus. Thus, a given slice of nucleus will not reliably contain all of the cell’s

DNA. Id.

LEGAL STANDARD

“A preliminary injunction is a provisional remedy, the purpose of which is to preserve status

quo and to prevent irreparable loss of rights prior to final disposition of the litigation.” Napa Valley

Publ’g Co. v. City of Calistoga, 225 F. Supp. 2d 1176, 1180 (N.D. Cal. 2002) (Chen, Mag. J.) (citing

Sierra On Line, Inc. v. Phoenix Software, Inc., 739 F.2d 1415, 1422 (9th Cir. 1984)). In light of

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these considerations, a plaintiff seeking preliminary injunctive relief must demonstrate either: “(1) a

likelihood of success on the merits and the possibility of irreparable injury; or (2) that serious

questions going to the merits [have been] raised and the balance of hardships tips sharply in [the

plaintiff’s] favor.” Southwest Voter Registration Educ. Project v. Shelley, 344 F.3d 914, 917 (9th

Cir. 2003) (en banc) (per curiam) (citing Clear Channel Outdoor, Inc. v. City of Los Angeles, 340

F.3d 810, 813 (9th Cir. 2003)); see also Sun Microsystems, Inc. v. Microsoft Corp., 188 F.3d 1115,

1119 (9th Cir. 1999). The components of these two tests, together with the added consideration of

the public interest, operate on a sliding scale or “continuum.” Southwest Voter, 344 F.3d at 918. 

Consequently, “the less certain the district court is of the likelihood of success on the merits, the

more plaintiffs must convince the district court that the public interest and balance of hardships tip in

their favor.” Id. (citation omitted); see also Miller v. California Pac. Med. Ctr., 19 F.3d 449, 456

(9th Cir. 1994) (en banc).

DISCUSSION

Dako challenges plaintiffs’ request for a preliminary injunction on a number of grounds. 

First, with respect to plaintiffs’ chance of prevailing on the merits, Dako offers a number of

arguments for why the accused kit does not infringe either asserted patent, and for why the asserted

patents are invalid and unenforceable. With respect to irreparable harm, Dako argues that sales of its

accused kit are currently minimal, that Dako is capable of satisfying any money judgment, and that

plaintiffs’ past conduct in prosecuting and then licensing the asserted patents belies any claim of

irreparable harm. Dako argues that it will face substantial hardship by being shut out of the market. 

Finally, Dako argues that public interest favors having multiple kits on the market that assist in the

treatment of breast cancer.

Plaintiffs dispute each of Dako’s arguments with respect to the likelihood of success on the

merits. Plaintiffs also argue that Dako poses a significant threat to Abbott’s market share by virtue

of Dako’s ability to exploit the existing market for its older kit. Abbott claims that it stands to lose a

number of multi-year contracts as a result of competition with Dako. Finally, plaintiffs argue that

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Dako’s entry into the market is particularly unjust given the large amount of time and expense that

Abbott has poured into the development and marketing of its own kit.

I. Likelihood of Success

In order to demonstrate a likelihood of success on the merits, plaintiffs must establish that

Dako’s HER2 kit likely infringes one of the asserted patents, and that Dako’s validity and

enforceability challenges to the asserted patents are likely to fail. See Oakley, Inc. v. Sunglass Hut

Int’l, 316 F.3d 1331, 1339–40 (Fed. Cir. 2003).

A. The ‘841 Patent

1. Infringement

Determination of infringement is a two-step process. First, the court must determine the

meaning of the language of the claims, a question of law. Markman v. Westview Instruments, Inc.,

517 U.S. 370, 384 (1996). Second, the finder of fact must compare the construed claims to the

accused product, to determine if each claim element is present, either literally or under the doctrine

of equivalents. Irdeto Access, Inc. v. Echostart Satellite Corp., 383 F.3d 1295, 1299 (Fed. Cir.

2004).

The ‘841 patent has only a single independent claim, claim 1, which reads as follows:

1. A method of staining target chromosomal DNA comprising: 

(a) providing 1) labeled nucleic acid that comprises fragments which are substantially

complementary to nucleic acid segments within the chromosomal DNA for which

detection is desired, and 2) blocking nucleic acid that comprises fragments which are

substantially complementary to repetitive segments in the labeled nucleic acid; and 

(b) employing said labeled nucleic acid, blocking nucleic acid, and chromosomal

DNA in in situ hybridization so that labeled repetitive segments are substantially

blocked from binding to the chromosomal DNA, while hybridization of unique

segments within the labeled nucleic acid to the chromosomal DNA is allowed,

wherein blocking of the labeled repetitive segments is sufficient to permit detection

of hybridized labeled nucleic acid containing unique segments, and wherein the

chromosomal DNA is present in a morphologically identifiable chromosome or

cell nucleus during the in situ hybridization.

‘841 patent at 17:4–25 (emphasis added). For purposes of opposing the motion for a preliminary

injunction, Dako claims that the accused kit does not meet two of the limitations of claim 1. First,

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Dako claims that the tissue samples on which the accused kit operates do not contain a

“morphologically identifiable” chromosome or cell nucleus because they are made up of slices of

cell nuclei containing interphase chromosomal material. Second, Dako argues that the kit does not

employ “blocking nucleic acid,” but instead uses PNAs, compounds comprising amino acid chains

(“peptides”) attached to nucleotide bases. 

a. “morphologically identifiable chromosome or cell nucleus”

i. Claim Construction

The parties agree that “morphologically identifiable chromosome” refers to a chromosome

that has consolidated in metaphase, and not a chromosome that is distributed throughout the nucleus

during interphase. The parties also agree that the accused kit does not make use of morphologically

identifiable chromosomes. The dispute centers on the meaning of “morphologically identifiable . . .

cell nucleus.” Dako proposes that “morphologically identifiable . . . cell nucleus” should be

construed to mean an “intact” nucleus—one that retains its entire complement of chromosomal

DNA. Plaintiffs contend that “morphologically identifiable . . . cell nucleus” should be construed to

mean “capable of being identified by its form and structure.” Plaintiffs’ proposed construction,

unlike Dako’s, does not require that the nucleus contain the full set of DNA.

In Regents of the University of California v. Oncor, 44 U.S.P.Q.2d 1321 (N.D. Cal. 1997)

(Walker, J.), this court already construed the phrase in claim 1 of the ‘841 patent that is at issue here. 

The parties in Oncor disputed whether the phrase “a morphologically identifiable chromosome or

cell nucleus” referred narrowly to a single target nucleus or chromosome, or more broadly to

multiple target nuclei or chromosomes. 44 U.S.P.Q.2d at 1324. UC Regents, the plaintiff in Oncor,

argued that the claimed process was limited to operation on a single nucleus because, among other

reasons, the principal advantage of the invention was the ability to “detect unique DNA sequences

on a single chromosome or cell nucleus.” Id. The defendant in Oncor argued that the disputed

phrase “merely clarifies that the target chromosomal DNA are present in intact chromosomes or cell

nuclei, but does not limit the number of these structures.” Id. After a review of the meaning of the

word “a,” the court reviewed the intrinsic record and concluded that the claim phrase was

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ambiguous. In light of the ambiguity, the court construed the phrase narrowly—against the

drafter—to refer to a single chromosome or cell nucleus. Id. at 1326.3

The doctrine of construing ambiguity “against” the drafter actually benefitted UC Regents

considerably, as the court’s narrow construction provided the basis for granting summary

adjudication that the claimed invention was not anticipated or rendered obvious by prior art. The

prior art processes in question, like the process described in the ‘841 patent, used unlabeled

repetitive sequences to prevent labeled probes from binding to the repetitive sites on the target

chromosomes. Id. at 1327. The prior art process, however, relied upon “frequency distribution

tables revealing the sites where the hybridizations were most likely to occur” because the binding

was not reliable enough to permit detection in a single cell. Id. As the prior art process did not

“permit detection of target chromosomal DNA on a single chromosome or cell nucleus” as required

by the court’s construction of the claim language, the court concluded as a matter of law that the

cited prior art did not invalidate the patent under 35 U.S.C. sections 102 or 103. Id. at 1328.

Plaintiffs claim not to contest the court’s construction in Oncor, but argue that the “single

cell nucleus” required by the ‘841 patent need not be completely intact.4 In support of their

argument, plaintiffs rely on a portion of the specification, which states that optimum practice of the

invention requires preparing the nucleus in a way that promotes easy hybridization, but “does not

cause unacceptable loss of morphological detail.” ‘841 patent at 11:66–67. According to plaintiffs,

this language suggests that the nucleus need not be completely intact, but must only retain enough of

its structure to remain recognizable. However, the portion of the specification cited by plaintiffs is

not helpful in resolving the issue in this case, which is whether the nucleus must retain its full set of

genetic material.

The court’s ruling in Oncor, on closer inspection, strongly favors Dako’s proposed

construction. According to the Oncor court, the claimed process must be able to “[detect]

hybridized labeled nucleic acid containing unique segments” in a single “morphologically

identifiable . . . cell nucleus.” Id. at 17:20–22. For the claimed process to operate successfully on a

single nucleus, that single nucleus must, at a minimum, contain the full set of chromosomal DNA. If

the single cell does not contain the full set of DNA, there is some chance that the portion of the

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DNA containing the target region is not present. A failure to detect the target in a single incomplete

set of DNA is therefore inconclusive.

Thus, combining the court’s express construction of the overall claim phrase in Oncor with

the implicit additional requirement that the cell nucleus contain the full complement of chromosomal

DNA, the court construes the phrase “morphologically identifiable . . .cell nucleus” to refer to a

single cell nucleus that contains the full complement of chromosomal DNA.

ii. Application to the Accused Kit

In light of the requirement that the target nucleus contain the full complement of

chromosomal DNA, it appears that plaintiffs will have great difficulty proving literal infringement. 

In Dako’s accused process, the target nuclei are presumed not to have a complete complement of

DNA. The Dako HER2 kit relies on two additional pieces of information to compensate for the loss

of chromosomal material in each sliced nucleus. First, the accused kit relies on counting target

regions across multiple partial nuclei. Schønau Dec. ¶ 8. Second, the accused kit uses a second

labeled probe, which bonds to exactly one location per full set of chromosomal material, to provide a

count of how many complete sets of chromosomes are present in the tissue sample. Id. Dividing the

total number of locations of the HER2 gene by the total number of complete sets of chromosomes

present yields the number of HER2 genes per cell, which is the desired result. Id.

The accused process is thus probabilistic; it depends on the aggregation of data from multiple

nuclei in order to yield an accurate count of the HER2 gene, and cannot reliably be performed on a

single formalin-fixed nucleus slice. In this respect, the accused process is similar to the prior art that

UC Regents expressly disclaimed in Oncor in order to preserve the validity of the ‘841 patent. 

Indeed, the argument advanced by plaintiffs is strikingly similar to the argument UC Regents

successfully opposed in Oncor. Plaintiffs in this case make the following argument:

During prosecution, when the “morphologically identifiable” limitation was added to

the claims, The Regents’ counsel specifically pointed to the specification’s

explanation that, with respect to the chromosomal DNA, it is important “not [to]

cause unacceptable loss of morphological detail.” . . . The amendment was made in

response to the Examiner’s concern that the term “chromosomal DNA” described

only the source of the target DNA, but not the form of the DNA. . . . In response, the

applicants explained that the chromosomal DNA is to be used in in situ hybridization

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and must therefore be in “some natural biological structure” although that structure

“may be partially dismantled to allow good hybridization.”

Pls.’ Reply Brief at 7 (emphasis in original). Similarly, in Oncor the defendant argued that the

phrase “morphologically identifiable” clarified “that the target chromosomal DNA are present in

intact . . . cell nuclei”—i.e., “some natural biological structure.” Oncor, 44 U.S.P.Q.2d at 1324. In

support of this argument, Oncor also cited the prosecution history:

Oncor argues that several exchanges in the prosecution history suggest that the last

phrase of step (b) was added to clarify the form of the target DNA, rather than their

[sic] number. This evidence consists, in part, of statements by the applicant that the

amended language was added to address the examiner’s concern that the

chromosomal DNA could have been processed prior to hybridization . . . and makes

clear that the chromosomal DNA retain their morphological detail.

Id. at 1325 (emphasis added). Oncor, like plaintiffs in this case, argued in essence that the

“morphologically identifiable . . . cell nucleus” limitation required only that the nucleus retain some

of its shape. As already noted, the Oncor court rejected this argument at the urging of UC Regents

and on that basis granted summary adjudication of validity over the prior art.

The court acknowledges that the source of uncertainty in the prior art—the lack of reliable

binding to only the unique regions—is different from the source of uncertainty in the accused kits,

which flows from the lack of a full set of chromosomes in any given cell nucleus slice. What UC

Regents disclaimed in order to prevail in Oncor, however, is broad: processes that require

hybridization in multiple nuclei. UC Regents might have argued Oncor differently in light of the

Dako kit, and plaintiffs may still find some valid basis for distinguishing Oncor in this case. The

court need not reach the ultimate question of whether plaintiffs will succeed in doing so; it is enough

to say that the reasoning of the Oncor court raises serious questions with respect to plaintiffs’

infringement argument in this case.

Plaintiffs argue that the’841 patent expressly contemplates hybridization in “fixed” tissue

samples such as those used in the accused kit. The ‘841 patent does state that as part of the

processing prior to hybridization the cells may be “fixed,” or hardened, through the application of

chemicals such as “acid alcohol solutions,” “acid acetone solutions,” or “various aldehydes such as

formaldehyde . . . .” Id. at 11:40–42. The ‘841 patent also states that the chromosomes may be

“treated with agents to remove proteins” prior to hybridization. Id. at 11:60–61. Defendant

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acknowledges that the accused kit also employs a hardening agent—formalin—and deproteinization

prior to hybridization. The problem with plaintiffs’ infringement position is not that the accused kit

uses fixatives, however, but that the accused kit operates on partial nuclei. The fact that the patent

contemplates the use of fixatives is therefore irrelevant.

Plaintiffs also argue that even if the tissue samples on which Dako’s kit operates do not

generally contain entire nuclei, even a single intact nucleus is all that is required for infringement. If

this intact nucleus could be identified and distinguished from the various partial nuclei, plaintiffs’

argument might have merit. Plaintiffs have presented no evidence, however, that it is possible to

determine by looking at the histologic sample which of the nuclei is intact, such that someone using

Dako’s kit could reliably detect the target region in a single cell nucleus.

Plaintiffs may be able to make some additional infringement argument that is not yet before

the court. On the basis of the current record, however, the court finds that plaintiffs have not

succeeded in establishing a likelihood of success on the merits with respect to infringement of the

“morphologically identifiable chromosome or cell nucleus” element.

b. “blocking nucleic acid”

Each claim of the ‘841 patent further requires that the process employ “blocking nucleic

acid” to reduce binding to repetitive sections. Plaintiffs acknowledge that the accused kit does not

literally contain “blocking nucleic acid,” but contend that PNA is equivalent to nucleic acid. As

Dako notes, determination of infringement under the Doctrine of Equivalents is a “highly factual

inquiry” which “rarely comes clear on a premature record.” Jeneric/Pentron, Inc. v. Dillon Co., 205

F.3d 1377, 1384 (Fed. Cir. 2000). Dako has submitted expert testimony in connection with its brief

in opposition that PNA probes accomplish blocking in a substantially different way from DNA

probes and are not “interchangeable” with DNA. For example, PNA probes can bind to DNA that

has not been denatured. Declaration of James Coull in Support of Defendant’s Opposition to

Plaintiff’s Motion for Preliminary Injunction (“Coull Dec.”) ¶¶ 23–26. PNA is also less susceptible

to changes in hybridization conditions, such as temperature. Id. The court is reluctant to make a

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factual finding as to infringement under the Doctrine of Equivalents, faced with conflicting credible

testimony, in the context of a motion for a preliminary injunction.

 The court therefore finds that plaintiffs have not succeeded in establishing a likelihood of

success on the merits with respect to infringement of the “blocking nucleic acid” element.

2. Validity and Enforceability

Dako notes that the Oncor court denied summary judgment as to two challenges to the

validity and enforceability of the ‘841 patent. This court need not consider the ultimate merits of

either challenge in order to resolve plaintiffs’ motion for a preliminary injunction, but finds that the

presence of fact issues as to validity and enforceability which could not be resolved on summary

judgment further diminishes plaintiffs’ likelihood of success. See, e.g., Oakley, 316 F.3d at 1339–40

(holding that an “injunction should not issue if the party opposing the injunction raises ‘a substantial

question concerning infringement or validity, meaning that it asserts a defense that [the party

seeking the injunction] cannot prove lacks substantial merit.’”) (citing Tate Access Floors, Inc. v.

Interface Architectural Resources, Inc., 279 F.3d 1357, 1365 (Fed.Cir.2002)).

B. The ‘479 Patent

1. Infringement

The ‘479 patent contains the same“morphologically identifiable chromosome or cell

nucleus” claim limitation that the court has already evaluated in the context of the ‘841 patent. For

the reasons already stated, the court finds that plaintiffs have not succeeded in establishing a

likelihood of success on the merits with respect to infringement of the “morphologically identifiable

chromosome or cell nucleus” element.

The claims of the ‘479 patent have a further problem vis-á-vis the accused kit in that they are

limited to the use of “a heterogeneous mixture of labeled unique sequence nucleic acid fragments.” 

‘479 patent at 16:9–10. Dako argues that this limitation excludes processes which employ probes

corresponding to repetitive sequences. Plaintiffs argue that the phrase should be construed to mean

“a heterogeneous mixture of labeled nucleic acid fragments that includes unique sequences,” but

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may also contain repetitive sequences.

Plaintiffs’ proposed construction is difficult to accept in light of the claims of the ‘841 patent,

which is prior art to the ‘479 patent under 35 U.S.C. section 102(b). Claim 1 of the ‘479 patent

explains that the “unique sequence nucleic acid fragments” are “substantially complementary to

nucleic acid segments within the interphase chromosomal DNA for which detection is desired.” Id.

at 16:10–13 (emphasis added). Likewise, the claims of the ‘841 patent require the use of “labeled

nucleic acid that comprises fragments which are substantially complementary to nucleic acid

segments within the chromosomal DNA for which detection is desired”—the very same phrase used

in the ‘479 patent. ‘841 patent at 17:6–12 (emphasis added). Claim 1 of the ‘841 patent further

requires “blocking nucleic acid that comprises fragments which are substantially complementary to

repetitive segments in the labeled nucleic acid.” Id. Plaintiffs’ proposed construction suggests that

the ‘479 patent, like the ‘841 patent, contemplates the use of both unique and repetitive probes. If

this is true, plaintiffs’ proposed construction appears to eliminate much of the difference between the

inventions claimed in the two patents.

It is not disputed that the accused kit makes use of probes having both unique and repetitive

sequences. The court therefore has serious concerns about plaintiffs’ ability to simultaneously

preserve validity and establish infringement with respect to the claims of the ‘479 patent.

For both of the reasons just discussed, the court finds that plaintiffs have not shown a

likelihood of success in proving infringement of any valid claim of the ‘479 patent.

2. Validity and Enforceability

The validity and enforceability challenges discussed in Oncor also apply to the ‘479 patent,

which contains the same specification as the ‘841 patent. For the reasons discussed above, the

presence of substantial validity and enforceability questions further weighs against the grant of an

injunction.

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II. Balance of Hardships

Having concluded that plaintiffs have not shown a likelihood of success on the merits, the

court now turns to whether they have shown that the balance of hardships tips sharply in their favor.

Plaintiffs argue that permitting Dako to continue selling the accused kit will irreparably harm

Abbott for three reasons. First, plaintiffs contend that Dako is using its existing customer base as

leverage in promoting sales of the accused kit, which Dako is allegedly “bundling” with the older kit

at a substantially discounted price. Plaintiffs argue that Dako’s discounted pricing will force Abbott

to reduce the price of its competing PathVysion kit. Second, plaintiffs contend that Dako’s

marketing of its accused kit as a “companion” to the older, protein-based test undermines Abbott’s

attempts to make its genomic PathVysion test the primary tool for detecting excess HER2 genes. 

Third, plaintiffs argue that Dako’s participation in the market for genomic tests erodes Abbott’s

position as a market leader.

Dako, in response, argues that its current market share of genomic tests is minimal and that it

will likely be able to satisfy any money judgment against it. Plaintiffs counter that the ability to

satisfy a money judgment is not sufficient to overcome the presumption of irreparable harm that

attaches in patent lawsuits. See, e.g., Polymer Techs., Inc. v. Bridwell, 103 F.3d 970, 975–76 (Fed.

Cir. 1996); Purdue Pharma L.P. v. Boehringer Ingelheim GMBH, 237 F.3d 1359, 1368 (Fed. Cir.

2001). As Dako correctly points out, a presumption of irreparable harm only attaches when the

patent holder establishes a likelihood of success on the merits. See id. at 1367 (“Purdue made a

clear showing of its likely success on the merits. Therefore, under the rule prevailing in our circuit,

Purdue was entitled to a rebuttable presumption of irreparable harm.”); Reiffin v. Microsoft Corp.,

158 F. Supp. 2d 1016, 1028 (N.D. Cal. 2001) (Walker, J.). Here, as already discussed, plaintiffs

have not shown a likelihood of success on the merits. Thus no presumption of irreparable harm

applies.

Unconstrained by any presumption, the court finds that plaintiffs’ alleged harms can be

addressed in the calculation of damages should they prevail in establishing infringement and should

Dako’s validity and enforceability challenges fail. See Nutrition 21 v. United States, 930 F.2d 867,

871 (Fed. Cir. 1991) (“neither the difficulty of calculating losses in market share, nor speculation

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that such losses might occur, amount to proof of special circumstances justifying the extraordinary

relief of an injunction prior to trial.”). The balance of hardships therefore do not tip sharply in

plaintiffs’ favor.

In sum, plaintiffs’ have failed to show either a likelihood of success on the merits or a

favorable balance of hardships. Preliminary injunctive relief is therefore inappropriate.

CONCLUSION

For the above reasons the court hereby DENIES plaintiffs’ motion for a preliminary

injunction.

IT IS SO ORDERED.

Date: March 10, 2006 ________________________

MARILYN HALL PATEL

United States District Judge

Northern District of California

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1. Unless otherwise noted, background facts are taken from the declarations submitted with the parties’

briefs, and are not in dispute.

2. Although the parties did not brief the issue in connection with the instant motion, it appears that

the ‘841 patent is limited to the use of blocking DNA which is complementary to labeled probes

containing repeat sequences, as opposed to the repeat sequences on the chromosomal DNA itself.

3. Dako also points to language earlier in the Oncor opinion, which explains the invention: “[t]his

process is known as in situ hybridization when it occurs on intact, or morphologically identifiable,

chromosomes or cell nuclei.” Id. at 1323. As plaintiffs point out, the quoted passage is not part of the

court’s claim construction. The quoted language suggests, at most, that the Oncor court assumed that

“morphologically identifiable” meant “intact,” without expressly so deciding.

4. Nor could plaintiffs reasonably do so. Regardless of general concerns of uniformity in construction

of the same claim terms in different lawsuits, see Markman, 517 U.S. at 391, plaintiffs would likely be

judicially estopped from advocating a different construction in this case. The Oncor court accepted UC

Regents’ construction, and the narrow construction was necessary to the court’s grant of summary

adjudication of lack of anticipation and obviousness. See generally New Hampshire v. Maine, 532 U.S.

742, 750 (2001). 

 ENDNOTES

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