DCT

1:19-cv-01804

CareDx Inc v. Eurofins Viracor Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-01804, D. Del., 09/26/2019
  • Venue Allegations: Venue is alleged to be proper as Defendant is a Delaware corporation and, on information and belief, uses, offers for sale, and/or sells the accused tests throughout the United States, including within the District of Delaware.
  • Core Dispute: Plaintiff alleges that Defendant’s diagnostic tests for monitoring organ transplant rejection infringe a patent related to the non-invasive detection of donor-derived cell-free DNA.
  • Technical Context: The technology concerns molecular diagnostics for organ transplant recipients, a field focused on replacing invasive tissue biopsies with sensitive blood tests to monitor for graft rejection.
  • Key Procedural History: The patent owner, The Board of Trustees of the Leland Stanford Junior University ("Stanford"), is named as a nominal defendant. The complaint states that Stanford, the exclusive licensor of the patent-in-suit to Plaintiff CareDx, refused a request to join the action as a co-plaintiff, compelling CareDx to name it as a nominal defendant to ensure standing.

Case Timeline

Date Event
2009-11-06 ’652 Patent Priority Date
2014-04-22 U.S. Patent No. 8,703,652 Issued
2019-00-00 (Early) Alleged start of Viracor's development of accused tests
2019-06-00 Viracor presents poster allegedly describing its infringing method
2019-09-26 Complaint Filed

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

U.S. Patent No. 8,703,652 - Non-Invasive Diagnosis of Graft Rejection in Organ Transplant Patients

The Invention Explained

  • Problem Addressed: The patent’s background section identifies the difficulty, expense, and inadequate sensitivity of then-current methods for monitoring organ transplant rejection, which often required invasive procedures (’652 Patent, col. 1:18-24). It specifically notes that surveillance for cardiac allograft vasculopathy (CAV) through coronary angiography is associated with high patient mortality once the condition is detected (’652 Patent, col. 5:56-6:13).
  • The Patented Solution: The invention provides a non-invasive method for detecting transplant rejection by measuring the amount of donor-derived cell-free DNA (dd-cfDNA) in a recipient’s bodily fluid, such as plasma (’652 Patent, col. 1:31-41). The process involves first creating a genetic "polymorphism profile" of both the donor and recipient to identify distinguishing genetic markers (e.g., Single Nucleotide Polymorphisms, or SNPs). After the transplant, a sample from the recipient is subjected to "shotgun sequencing," and the resulting data is analyzed to count the DNA fragments that match the donor’s unique genetic profile. An increase in the quantity of donor DNA over time indicates a higher likelihood of transplant rejection (’652 Patent, Fig. 5; col. 8:56-9:17).
  • Technical Importance: The complaint asserts that this method represented a major advance by providing a "universal approach" applicable to all organ recipients, irrespective of the gender of the donor and recipient, overcoming a key limitation of prior art techniques that relied on detecting Y-chromosome DNA (Compl. ¶¶23-24; ’652 Patent, col. 8:45-54).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶17).
  • Essential elements of independent claim 1 include:
    • (a) providing a sample with cell-free nucleic acids from a transplant recipient.
    • (b) obtaining a genotype of donor-specific and/or subject-specific polymorphisms to establish a "polymorphism profile," where at least one SNP is homozygous for the subject.
    • (c) performing "multiplex sequencing" of the cell-free nucleic acids and analyzing the results using the polymorphism profile to detect donor and subject DNA.
    • (d) diagnosing, predicting, or monitoring transplant status by determining the quantity of donor DNA, where an increase over time is indicative of rejection and where the method has a sensitivity greater than 56% for cardiac allograft vasculopathy.
  • The complaint reserves the right to assert other claims of the ’652 patent (Compl. ¶37).

III. The Accused Instrumentality

Product Identification

The Viracor TRAC™ Kidney dd-cfDNA, Viracor TRAC™ Heart dd-cfDNA, and Viracor TRAC™ Lung dd-cfDNA tests (collectively, the "TRAC™ tests") (Compl. ¶10).

Functionality and Market Context

  • The complaint alleges the TRAC™ tests are designed to "determine the percentage of circulating cell-free DNA (cfDNA) in transplant recipients derived from donor grafts" (Compl. ¶28). The process allegedly involves extracting cfDNA from a patient's blood plasma, performing "unbiased sequencing," and using a bioinformatics pipeline that analyzes "NGS [Next-Generation Sequencing] and genome-wide recipient genotype data" to calculate the percentage of donor-derived cfDNA (Compl. ¶¶27-28). The complaint references a Viracor website (Ex. 4) which states that the test assigns Test Code 30877 and requires special tubes for collection (Compl. ¶26).
  • The complaint alleges that Viracor's parent company's CEO highlighted the "significant commercial potential" of these tests and noted their similarity to products offered by CareDx (Compl. ¶25).

IV. Analysis of Infringement Allegations

The complaint references an exemplary claim chart (Exhibit 10) but does not include the exhibit in the filing (Compl. ¶32, ¶37). The infringement theory is therefore summarized from the narrative allegations.

The complaint alleges that Viracor’s TRAC™ tests practice the method of claim 1 of the ’652 patent (Compl. ¶31). The core of the infringement theory is that Viracor's method for quantifying dd-cfDNA corresponds to the patented method. Specifically, the complaint alleges that Viracor’s use of "NGS and genome-wide recipient genotype data" (Compl. ¶¶27-28) satisfies the "multiplex sequencing" and "obtaining a genotype" limitations. The complaint further alleges that Viracor’s method is based on a publication (the "Sharon article") that describes estimating dd-cfDNA by "focusing only on the homozygous genomic loci of the recipient" (Compl. ¶¶29-30). This directly corresponds to language in claim 1(b) requiring that "at least one single nucleotide polymorphism (SNP) is homozygous for the subject." The complaint references a poster presented by Viracor (Exh. 11), which allegedly confirms its use of a method "Licensed from Stanford University" that corresponds to the Sharon article, as further evidence of infringement (Compl. ¶30).

Identified Points of Contention

  • Scope Questions: A central question for the court will be whether Viracor's alleged method of using only "recipient genotype data" and a "licensed algorithm" to quantify donor DNA "without need for donor genotype information" (Compl. ¶27) falls within the scope of claim 1(b), which requires "obtaining a genotype ... to establish a polymorphism profile for detecting donor cell-free nucleic acids." The analysis will likely focus on whether Viracor’s process constitutes "establishing a polymorphism profile" as construed from the patent.
  • Technical Questions: What evidence demonstrates that Viracor's actual, operational "bioinformatics pipeline" (Compl. ¶28) performs the specific steps recited in the claims? The court will examine whether the accused TRAC™ tests, as practiced, align with the methods described in the Sharon article and the Viracor poster, and whether those methods in turn meet all limitations of the asserted claim.

V. Key Claim Terms for Construction

  • The Term: "obtaining a genotype ... to establish a polymorphism profile" (Claim 1(b))
  • Context and Importance: The definition of this term is critical because the complaint alleges Viracor's method works "without need for donor genotype information," relying instead on "genome-wide recipient genotype data" and an algorithm (Compl. ¶¶27-28). The case may turn on whether this process meets the "establishing a polymorphism profile" limitation. Practitioners may focus on this term because it appears to be the primary point of technical dispute between the patent's requirements and the accused product's alleged functionality.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discusses genotyping in general terms, stating that "both the donor and recipient will be genotyped prior to transplantation" using methods that "include, but are not limited to, whole genome sequencing, exome sequencing, or polymorphisms arrays" (’652 Patent, col. 8:56-61). This broad language may support an interpretation that is not limited to a specific technique.
    • Evidence for a Narrower Interpretation: The detailed description of the invention repeatedly frames the solution around a comparison between donor and recipient genotypes (’652 Patent, Fig. 5; col. 13:1-6). A defendant may argue that "to establish a polymorphism profile for detecting donor cell-free nucleic acids" requires actively genotyping both parties to create a comparative profile, not just analyzing the recipient's genome with an algorithm.

VI. Other Allegations

  • Indirect Infringement: The complaint does not contain allegations of indirect or contributory infringement. It asserts direct infringement under 35 U.S.C. § 271(a) (Compl. ¶37).
  • Willful Infringement: The complaint does not explicitly allege "willful infringement." However, it requests a determination that the case is "exceptional" under 35 U.S.C. § 285, which permits an award of attorney's fees (Compl., Prayer for Relief ¶D). The factual basis for this appears to be the allegation that Viracor was aware of CareDx's similar products and technology, as suggested by an earnings call from Viracor's parent company (Compl. ¶25).

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

  1. A central issue will be one of claim scope and technical infringement: Does Viracor's diagnostic method, which allegedly quantifies donor DNA using only recipient genotype data and a proprietary algorithm, practice the patented method which requires "obtaining a genotype...to establish a polymorphism profile for detecting donor cell-free nucleic acids"? The resolution will depend heavily on claim construction and the factual evidence of how the accused tests operate.

  2. A second key issue, anticipated by the plaintiff, will be one of patent eligibility under 35 U.S.C. § 101: Is Claim 1 directed to a patent-ineligible natural phenomenon (the correlation between dd-cfDNA levels and transplant rejection), or is it directed to a specific, inventive application of that discovery? The complaint’s arguments that the claim requires a series of concrete, unconventional laboratory steps suggest this will be a primary legal battleground in the case (Compl. ¶¶18-19).