DCT

7:13-cv-05669

CDx Diagnostics Inc v. United States Endoscopy Group Inc

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 7:13-cv-05669, S.D.N.Y., 08/13/2013
  • Venue Allegations: Venue is alleged to be proper because Defendant conducts business in the district, has committed acts of infringement in the district, and places the accused products into a stream of commerce directed at New York.
  • Core Dispute: Plaintiffs allege that Defendant’s "Infinity" line of endoscopic biopsy brushes infringes three patents related to non-lacerational, retractable brushes for collecting transepithelial tissue samples.
  • Technical Context: The technology concerns specialized brushes for use with endoscopes to obtain cell samples from internal tissues for biopsy, a procedure critical for the early detection of cancers and other diseases.
  • Key Procedural History: The complaint alleges that Plaintiff CDX provided Defendant with notice of U.S. Patent No. 6,258,044 in a letter dated March 18, 2004, concerning a prior product. After this case was filed, all asserted claims of all three patents-in-suit were cancelled in separate Inter Partes Review (IPR) proceedings before the U.S. Patent and Trademark Office, with certificates issuing in February 2018. This subsequent invalidation of the asserted patent claims is a dispositive event for the litigation.

Case Timeline

Date Event
1998-07-23 U.S. Patent No. 6,258,044 Priority Date
2001-05-04 U.S. Patent Nos. 6,676,609 & 7,004,913 Priority Date
2001-07-10 U.S. Patent No. 6,258,044 Issues
2004-01-13 U.S. Patent No. 6,676,609 Issues
2004-03-18 Plaintiff sends notice letter to Defendant regarding '044 Patent
2006-02-28 U.S. Patent No. 7,004,913 Issues
2013-08-13 Complaint Filed

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

  • U.S. Patent No. 6,258,044, “APPARATUS AND METHOD FOR OBTAINING TRANSEPITHELIAL SPECIMEN OF A BODY SURFACE USING A NON-LACERATING TECHNIQUE,” issued July 10, 2001

    • The Invention Explained:
      • Problem Addressed: The patent describes a "diagnostic dilemma" where prior art cytology brushes are too soft to penetrate the protective keratin layer of many oral lesions, leading to a high rate of false negatives for cancer detection, while surgical biopsy is painful, costly, and often delayed ('044 Patent, col. 2:1-14, col. 4:10-16).
      • The Patented Solution: The invention is a brush with stiff, semi-rigid bristles designed to penetrate all three layers of the epithelium (superficial, intermediate, and basal) down to the basement membrane without causing a surgical-style laceration. This "drilling" action aims to collect a complete "transepithelial" cell sample that is functionally equivalent to a biopsy specimen ('044 Patent, col. 4:55-61, col. 10:35-49; Fig. 11).
      • Technical Importance: The technology sought to provide a minimally invasive, office-based procedure that could yield a cell sample as diagnostically reliable as a surgical biopsy, thereby improving early cancer detection rates ('044 Patent, col. 5:10-16).
    • Key Claims at a Glance:
      • The complaint asserts one or more claims, including independent apparatus claim 12.
      • Essential elements of independent claim 12 include:
        • A transepithelial non-lacerational sampling apparatus to harvest cells from epithelial tissue comprising superficial, intermediate, and basal layers.
        • The apparatus comprises "means to traverse said superficial, intermediate and basal layers and to collect cells from said three layers."
      • The complaint does not explicitly reserve the right to assert dependent claims.

  • U.S. Patent No. 7,004,913, “RETRACTABLE BRUSH FOR USE WITH ENDOSCOPE FOR BRUSH BIOPSY,” issued February 28, 2006

    • The Invention Explained:
      • Problem Addressed: The patent identifies a need for improved cell sampling techniques for internal body tissues, such as metaplastic glandular epithelium, that are accessible only via an endoscope and where superficial sampling may be insufficient for an accurate diagnosis ('913 Patent, col. 5:24-30).
      • The Patented Solution: The invention discloses a retractable brush that can be passed through the working channel of an endoscope. The brush features bristles stiff enough to exert sufficient pressure to dislodge and collect cells not just from the surface of the tissue, but from the "tissue area therebelow," thereby obtaining a more complete, disaggregated sample of the whole tissue without laceration ('913 Patent, col. 6:45-59, col. 10:45-50).
      • Technical Importance: This invention adapted the transepithelial biopsy concept for use in endoscopic procedures, extending the potential for more accurate, minimally invasive diagnostics to internal organs like the esophagus ('913 Patent, col. 6:60-65).
    • Key Claims at a Glance:
      • The complaint asserts one or more claims, including independent apparatus claim 1.
      • Essential elements of independent claim 1 include:
        • An apparatus for use with an endoscope to sample cells from glandular epithelium, which has an outermost surface and a tissue area below.
        • A rod passing through a channel in the endoscope.
        • A "retractable non-lacerational brush" attached to the rod.
        • The brush has bristles that exert "sufficient pressure to dislodge cells and to pick up a specimen from said uppermost surface and said tissue area therebelow."
      • The complaint does not explicitly reserve the right to assert dependent claims.

  • Multi-Patent Capsule: U.S. Patent No. 6,676,609

    • Patent Identification: U.S. Patent No. 6,676,609, "RETRACTABLE BRUSH FOR USE WITH ENDOSCOPE FOR BRUSH BIOPSY," issued January 13, 2004.
    • Technology Synopsis: This patent, part of the same family as the ’913 Patent, describes an apparatus for obtaining a biopsy via an endoscope. It discloses a retractable brush with bristles stiff enough to penetrate below the superficial tissue layer to collect a more comprehensive cell sample, overcoming the limitations of conventional, softer cytology brushes. (’609 Patent, Abstract; col. 6:45-59).
    • Asserted Claims: The complaint asserts one or more claims, including independent claim 1.
    • Accused Features: The "Infinity Sampling Device" and "Infinity Cytology Device" are accused of embodying the claimed invention (Compl. ¶16, ¶27).

III. The Accused Instrumentality

  • Product Identification: The "Infinity Sampling Device" and the "Infinity Cytology Device" (Compl. ¶16).
  • Functionality and Market Context:
    • The accused products are endoscopic sampling devices designed for collecting cell samples from strictures in the biliary duct and other areas of the GI tract (Compl., Ex. 2, p. 50, 52).
    • A product advertisement included in the complaint describes the "Infinity" device as featuring a unique bristle configuration with "stiffer bristles to help create a defect in the tissue" and "softer bristles to capture abraded material" (Compl., Ex. 2, p. 50). It also highlights "spaces between the bristles to help pack cells into the catheter" (Compl., Ex. 2, p. 50).
    • A product image with callouts illustrates the distinct types of bristles on the brush head (Compl., Ex. 2, p. 50).
    • The complaint alleges these products are currently being offered for sale and sold by the Defendant throughout the United States (Compl. ¶16).

IV. Analysis of Infringement Allegations

  • '044 Patent Infringement Allegations
Claim Element (from Independent Claim 12) Alleged Infringing Functionality Complaint Citation Patent Citation
A transepithelial non-lacerational sampling apparatus to harvest cells in an oral cavity from the epithelial tissue, said epithelial tissue comprising superficial, intermediate and basal layers... The complaint alleges the accused "Infinity" devices are sampling apparatuses that embody the inventions of the ’044 Patent. ¶21 col. 5:5-10
...said non-lacerational sampling apparatus comprising means to traverse said superficial, intermediate and basal layers and to collect cells from said three layers. The accused devices' advertised "stiffer bristles to help create a defect in the tissue" are alleged to constitute the means for traversing the tissue layers to collect a transepithelial sample. ¶21; Ex. 2, p. 50 col. 4:55-61
  • '913 Patent Infringement Allegations
Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An apparatus to be used in conjunction with an endoscope to examine tissue cells located within glandular epithelium... The accused "Infinity" devices are advertised for use in endoscopic procedures such as ERCP to collect samples from the biliary duct, an area containing glandular epithelium. ¶27; Ex. 2, p. 50 col. 9:33-36
a retractable non-lacerational brush attached to the distal end of the rod... The accused products are brushes designed to be passed through an endoscope, which implies they are retractable within the endoscope's channel. ¶27; Ex. 2, p. 50, 52 col. 6:30-38
...said brushing apparatus comprising bristles which exert sufficient pressure to dislodge cells and to pick up a specimen from said uppermost surface and said tissue area therebelow. The combination of "stiffer bristles to help create a defect in the tissue" and "softer bristles to capture abraded material" is alleged to perform the claimed function of dislodging and collecting cells from both the surface and subsurface. ¶27; Ex. 2, p. 50 col. 10:45-50
  • Identified Points of Contention:
    • Scope Questions: A central dispute may arise over the term "non-lacerational." The patents use this term to distinguish the invention from a "scalpel" or surgical biopsy ('609 Patent, col. 6:22-29). The question is whether the accused product's function of "creat[ing] a defect in the tissue" (Compl., Ex. 2, p. 50) falls within the scope of "non-lacerational" or is instead a form of micro-laceration that the patents sought to avoid.
    • Technical Questions: The complaint relies on marketing materials to allege infringement. A key technical question for the court would be what evidence demonstrates that the accused products actually collect a transepithelial sample (from all three layers, per the ’044 Patent) or a specimen from the "tissue area therebelow" (per the ’913 Patent), as opposed to merely abrading the surface more aggressively than prior art brushes.

V. Key Claim Terms for Construction

  • The Term: "non-lacerational"

    • Context and Importance: This term is fundamental to the patents' positioning against prior art surgical biopsies. Its construction is critical because the accused product is advertised to "create a defect in the tissue," creating a potential conflict. Practitioners may focus on this term to determine if the accused product's mode of action is the same as, or different from, the patented method.
    • Intrinsic Evidence for a Broader Interpretation: The specification contrasts "non-lacerational" with a "scalpel procedure" and notes that the invention may cause "minor discomfort and or bleeding," suggesting that some level of tissue disruption is contemplated ('609 Patent, col. 6:22-29).
    • Intrinsic Evidence for a Narrower Interpretation: The patents emphasize obtaining a sample "without the pain or injury of lacerational biopsies" ('609 Patent, col. 5:46-48). A party could argue that intentionally creating a "defect" constitutes a form of injury or micro-laceration that the invention was designed to avoid.

  • The Term: "bristles which exert sufficient pressure to... pick up a specimen... located below the surface of said epithelium tissue" (from '609 Patent, Claim 1)

    • Context and Importance: This functional language defines the core mechanism of the invention. The infringement analysis will depend on whether the dual-bristle design of the accused product performs this specific function.
    • Intrinsic Evidence for a Broader Interpretation: The specification describes using a "stiff-bristled brush" and "rubbing harder than normal" to "reach to the basement membrane without lacerating" ('609 Patent, col. 6:45-53). This supports an interpretation where stiff bristles are the primary means of obtaining the sub-surface sample.
    • Intrinsic Evidence for a Narrower Interpretation: The claim requires that the bristles not only dislodge cells but also "pick up a specimen" from below the surface. A defendant might argue that its "stiffer bristles" only "create a defect" while its "softer bristles" only "capture abraded material," potentially arguing a mismatch with the claimed function if the collected specimen is not proven to be from the sub-surface layer.

VI. Other Allegations

  • Indirect Infringement: The complaint includes allegations that Defendant will continue to "induce infringement" of the patents-in-suit, but does not plead specific supporting facts, such as instructing users via manuals or training to perform the claimed methods (Compl. ¶23, ¶29).
  • Willful Infringement: The complaint alleges that Defendant's infringement is willful and deliberate. This allegation is supported by the claim that Defendant has had "actual knowledge" of the ’044 Patent since at least March 18, 2004, as a result of a notice letter sent by Plaintiff CDX (Compl. ¶14, ¶25). For the ’913 and ’609 Patents, the complaint makes a general allegation of actual knowledge without specifying the date or means of notice (Compl. ¶31).

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

  • A central, and ultimately dispositive, issue for this case is one of validity: With all asserted claims of all three patents-in-suit having been cancelled in IPR proceedings after the complaint was filed, the legal basis for the infringement action was extinguished, rendering the dispute moot.
  • At the time of filing, a core issue would have been one of definitional scope: Can the term "non-lacerational," which the patents define in opposition to surgical cutting, be construed to cover a device that is marketed to "create a defect in the tissue"?
  • A key evidentiary question would have been one of functional performance: Does the accused device's combination of "stiffer" and "softer" bristles perform the specific function of collecting a transepithelial specimen as required by the claims, or does it operate in a technically distinct manner that falls outside the patent's scope?