Roche Diagnostics Corp v. Cholestech Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Roche Diagnostics Corporation (Indiana) and Roche Diagnostics GmbH (Germany)
  • Defendant: Cholestech Corporation (California)
  • Plaintiff’s Counsel: Baker & Daniels; McDonnell Boehnen Hulbert & Berghoff
• Case Identification: 1:03-cv-0303, S.D. Ind., 03/03/2003
• Venue Allegations: Venue is alleged to be proper based on Defendant’s distribution and sale of products throughout the United States, including substantial sales within the Southern District of Indiana.
• Core Dispute: Plaintiffs allege that Defendant’s point-of-care blood testing system, comprising a handheld monitor and disposable test cassettes, infringes three patents related to methods and apparatuses for rapidly separating lipoproteins to measure HDL cholesterol.
• Technical Context: The technology pertains to rapid diagnostic testing for cholesterol, a key biomarker used in assessing the risk of coronary heart disease, by enabling integrated sample processing within a disposable device.
• Key Procedural History: The complaint alleges that on January 8, 2003, prior to the filing of this action, a German Regional Court found Defendant Cholestech liable for infringing the German counterparts of the patents-in-suit. This prior foreign adjudication may be presented as evidence of pre-suit notice for the purpose of establishing willful infringement.

Date	Event
1989-09-01	Priority Date for '849, '164, and '570 Patents
1998-07-28	U.S. Patent 5,786,164 Issued
2001-01-09	U.S. Patent 6,171,849 Issued
2001-04-10	U.S. Patent 6,214,570 Issued
2003-01-08	German court finds infringement of counterpart patents
2003-03-03	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 6,171,849 - “Method for the Determination of HDL Cholesterol by Means of a Rapid Diagnostic Agent with an Integrated Fractionating Step” (Issued Jan. 9, 2001)

The Invention Explained

Problem Addressed: The patent identifies that conventional methods for measuring HDL cholesterol, a key step in cardiac risk assessment, are ill-suited for routine diagnostics because they rely on "expensive, time-consuming" laboratory procedures like ultracentrifugation to separate lipoproteins ('849 Patent, col. 1:39-43). These complex workflows require significant time and specialized equipment, and introduce potential sources of measurement error ('849 Patent, col. 2:1-6).

The Patented Solution: The invention is an apparatus, such as a test strip, that integrates lipoprotein separation and analysis into a single device. It employs a multi-layer structure where a fluid sample first contacts a "first porous carrier" containing a "releasable precipitating agent" ('849 Patent, col. 7:16-19). This agent dissolves into the sample and selectively precipitates non-HDL lipoproteins. The sample then flows to a "second porous carrier" which physically traps the precipitated non-HDLs but allows the fluid containing the desired HDL to pass through for analysis ('849 Patent, col. 7:23-26; Fig. 1).

Technical Importance: This integrated design enables rapid, point-of-care HDL cholesterol testing from a small sample, eliminating the need for separate, complex laboratory separation steps ('849 Patent, col. 4:65–col. 5:14).

Key Claims at a Glance

• The complaint asserts infringement of unspecified claims. The patent’s independent claims are Claim 1 and Claim 2.
• Independent Claim 1 (apparatus for separation): An apparatus comprising:
  • a first porous carrier permitting fluid flow-through and containing a "releasable precipitating agent" for non-HDL that is "soluble" in the fluid sample; and
  • a second porous carrier that permits fluid flow-through but "retains precipitated non-HDLs."
• Independent Claim 2 (apparatus for determination): An apparatus comprising the elements of Claim 1, plus:
  • an agent for determining cholesterol as a measure for HDL cholesterol.
• The complaint reserves the right to assert dependent claims.

U.S. Patent No. 5,786,164 - “Method for Separating Non-High Density Lipoproteins from Lipoprotein Containing Body Fluid Samples” (Issued Jul. 28, 1998)

The Invention Explained

Problem Addressed: The patent's background describes existing HDL measurement techniques involving precipitation and centrifugation as "much too time-consuming for a routine test" and requiring "complicated additional equipment" ('164 Patent, col. 2:1-4).

The Patented Solution: The invention claims a method for achieving rapid separation of non-HDL lipoproteins. The method involves contacting a body fluid sample with a first porous carrier containing a precipitating agent, which causes non-HDLs to precipitate ('164 Patent, col. 7:11-16). The fluid is then contacted with a second porous carrier that physically retains the precipitated non-HDLs, allowing the remaining fluid containing HDL to be separated for analysis. A key feature of the claimed method is that the entire process of precipitation and separation occurs "within a time period of one minute or less" ('164 Patent, col. 7:19-21).

Technical Importance: The invention provides a method that simplifies and accelerates HDL testing, making it feasible to perform outside of a traditional laboratory setting without specialized equipment ('164 Patent, col. 2:9-14).

Key Claims at a Glance

• The complaint asserts infringement of unspecified claims. The patent’s independent claims are Claim 1 and Claim 2.
• Independent Claim 1 (method for determination): A method comprising:
  • contacting a sample to a first porous carrier with a precipitating agent;
  • contacting the sample to a second porous carrier that retains the precipitate;
  • completing these steps within one minute or less; and
  • determining cholesterol in the resulting fluid as a measure of HDL.
• Independent Claim 2 (method for separation): A method comprising:
  • contacting a sample to a porous carrier with a precipitating agent;
  • separating the resulting fluid by contacting it to a second porous carrier that retains the precipitate;
  • completing these steps within one minute or less.
• The complaint reserves the right to assert dependent claims.

U.S. Patent No. 6,214,570 - “Method for Separating Non-HDLs from HDLs, and Determining, HDL Cholesterol” (Issued April 10, 2001)

• Patent Identification: U.S. Patent No. 6,214,570, “Method for Separating Non-HDLs from HDLs, and Determining, HDL Cholesterol,” Issued April 10, 2001 (Compl. ¶9).
• Technology Synopsis: This patent claims a method for separating and measuring HDL cholesterol that mirrors the technology of its parent patents. It addresses the need to replace slow, complex laboratory procedures with a rapid, integrated system ('570 Patent, col. 2:1-14). The claimed method involves applying a sample to a first carrier containing a soluble precipitating agent, which precipitates non-HDLs, and then contacting the sample to a second carrier that traps the precipitate while allowing unprecipitated HDLs to pass through for analysis ('570 Patent, cl. 1).
• Asserted Claims: The complaint does not specify which claims are asserted; the patent contains independent claims 1 and 12.
• Accused Features: The complaint alleges that the use of the Cholestech LDX device and its disposable test cassettes constitutes practice of the method claimed in the '570 patent (Compl. ¶22).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are the "Cholestech LDX device" and its associated disposable test cassettes (Compl. ¶¶10-11).

Functionality and Market Context

• The system is described as a "hand-held monitor" for "near patient blood testing" that uses disposable cassettes to measure biological markers, including HDL cholesterol (Compl. ¶¶10-11).
• The complaint specifically identifies four accused test cassettes used for HDL measurement: the "TC and HDL Panel – 11," "TC.HDL.Glu.Panel," "Lipid Profile," and "Lipid Profile Plus Glucose" (Compl. ¶11).
• It is alleged that Cholestech sells these cassettes along with instructions for their use, which may form the basis for allegations of induced infringement (Compl. ¶11, ¶17).

IV. Analysis of Infringement Allegations

The complaint, filed under pre-Twombly/Iqbal pleading standards, does not contain specific factual allegations mapping the features of the accused products to the elements of the asserted claims. The infringement theory is stated in conclusory terms, alleging that the manufacture, use, and sale of the Cholestech LDX device and its HDL test cassettes infringe the asserted patents (Compl. ¶¶14, 17, 22). No probative visual evidence provided in complaint. Due to the lack of detailed allegations, a claim-chart summary cannot be constructed.

• Identified Points of Contention:
  • '849 Patent (Apparatus):
    • Technical Question: A key factual dispute will be whether the Cholestech cassettes are constructed with the two-carrier system claimed in the patent. This will require evidence on if the cassettes contain a "first porous carrier" with a "releasable precipitating agent" and a physically distinct "second porous carrier" that "retains" the precipitate.
    • Scope Question: The construction of "retains precipitated non-HDLs" will be critical. The parties may dispute whether this term requires complete retention of the precipitate or if partial retention is sufficient to meet the limitation.
  • '164 Patent (Method):
    • Technical Question: Does operation of the accused system perform the claimed method steps in the required sequence? The analysis will turn on evidence of the internal chemical and physical processes that occur when a sample is applied to a Cholestech cassette.
    • Scope Question: A central issue for the method claims will be the temporal limitation requiring precipitation and separation "within a time period of one minute or less." Proving infringement will require evidence demonstrating the kinetics of the process within the accused device meet this timing requirement.

V. Key Claim Terms for Construction

• The Term: "releasable precipitating agent" ('849 Patent, cl. 1)

  • Context and Importance: This term defines the chemical component responsible for initiating the separation. Its construction is critical to determining whether the agent used in the Cholestech cassettes falls within the scope of the claims, particularly the requirements that it be both "releasable" and "soluble."
  • Intrinsic Evidence for a Broader Interpretation: The specification suggests a broad range of suitable agents, stating that various polyanions can be combined with various bivalent cations, not just those in the preferred embodiments ('164 Patent, col. 3:1-10).
  • Intrinsic Evidence for a Narrower Interpretation: The patent provides specific examples, such as "dextran sulphate with a molecular weight of 50000" combined with magnesium acetate, which could be used to argue for a construction limited to agents with similar properties ('164 Patent, col. 3:11-18; EXAMPLES 1–3).

• The Term: "second porous carrier which... retains precipitated non-HDLs" ('849 Patent, cl. 1)

  • Context and Importance: This term defines the physical filtration mechanism. The dispute will likely focus on the structure of the accused device's filter and the degree of "retention" it achieves.
  • Intrinsic Evidence for a Broader Interpretation: The specification describes this element functionally as being "capable of taking up fluid free of precipitate" and generally as a "fibre mesh" ('849 Patent, col. 4:2-3, 4:27-29). This language may support a construction based on the function of separation rather than a specific structure.
  • Intrinsic Evidence for a Narrower Interpretation: The patent discloses highly specific embodiments, such as a "fibre mesh" made of borosilicate glass and cellulose fibers in a 9:1 ratio with specific weight and thickness characteristics ('164 Patent, col. 5:51-56). A defendant may argue that the claim scope should be tethered to these detailed examples.

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement for all three patents (Compl. ¶¶14, 17-18, 22-23). The factual basis for inducement is the allegation that Cholestech sells its test cassettes with "information sufficient to actively induce its customers to infringe" (Compl. ¶17, ¶22). Contributory infringement is based on the allegation that the cassettes are "especially made or especially adapted for use in an infringement" and are not staple articles of commerce (Compl. ¶18, ¶23).
• Willful Infringement: Willfulness is alleged for all asserted patents (Compl. ¶¶15, 20, 25). The primary factual basis for this claim is the allegation that Cholestech had pre-suit knowledge of infringement because of a January 8, 2003 judgment from a German court finding that Cholestech infringed the "corresponding German counterpart" patents (Compl. ¶12).

VII. Analyst’s Conclusion: Key Questions for the Case

• Impact of Foreign Litigation: A core issue will be the evidentiary weight and influence of the prior German court decision. While not legally binding on the U.S. case, Plaintiffs will likely present the German judgment as powerful evidence of pre-suit knowledge, which is central to the claim of willful infringement and any subsequent request for enhanced damages.
• Structural Mapping: The case will likely turn on a fundamental question of structural and functional correspondence: does the internal architecture of the Cholestech cassettes embody the two-carrier separation system claimed in the '849 patent, or does it achieve HDL separation through a different, non-infringing design?
• Methodology and Timing: For the asserted method claims ('164 and '570 Patents), a key evidentiary hurdle for Roche will be demonstrating that the use of the accused system not only performs the claimed sequence of steps but does so "within a time period of one minute or less." This will require detailed technical evidence on the reaction kinetics and fluid dynamics inside the accused cassettes.