563 F.Supp.3d 329
D. Del.2021Background
- Plaintiffs CareDx sued Natera and Eurofins for infringement of three related patents (U.S. Pat. Nos. 8,703,652; 9,845,497; 10,329,607) that claim non‑invasive methods to detect or quantify donor‑derived cell‑free DNA (cfDNA) to diagnose or predict transplant rejection.
- Representative claims recite four basic steps: (1) obtain a recipient sample containing cfDNA; (2) genotype donor and/or recipient to develop SNP/polymorphism profiles; (3) perform multiplex/high‑throughput sequencing or digital PCR; and (4) determine/quantify donor cfDNA (thresholds such as 0.03% and sensitivity metrics appear in claims).
- The patents share a 2009 priority date; the correlation between donor cfDNA and rejection was long known before 2009. The specification repeatedly states the recited laboratory techniques are conventional and within the skill of the art.
- Defendants moved for § 101 dismissal/summary judgment arguing the claims are directed to a natural phenomenon and add only conventional steps; the district court initially denied summary judgment because of competing expert evidence, then sua sponte reopened the issue, held an evidentiary hearing, and invited supplemental briefing.
- The court found no genuine dispute of material fact that the specification admitted the recited techniques were conventional and therefore that the claims are directed to patent‑ineligible subject matter under § 101; it granted summary judgment for the defendants.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether asserted claims are directed to patent‑ineligible subject matter under 35 U.S.C. § 101 | Claims are directed to concrete, novel methods for detecting donor cfDNA that improve prior assays and are non‑conventional in application to cfDNA | Claims merely detect a natural phenomenon (donor cfDNA / its correlation with rejection) and use only conventional, routine lab techniques | Held: Claims are directed to a natural phenomenon and thus implicate § 101 (Alice step 1) |
| If directed to a natural phenomenon, whether claims contain an "inventive concept" (Alice step 2) | The particular combination/application of sequencing, genotyping, and quantification is novel and non‑routine so it supplies the inventive concept | The specification admits each claimed technique is conventional; the combination adds nothing significant beyond well‑understood, routine steps | Held: No inventive concept — additional claim elements are conventional and do not transform the natural phenomenon into patent‑eligible subject matter |
| Whether extrinsic evidence (expert testimony, literature) can create a genuine dispute overcoming the specification's statements that techniques are conventional | Extrinsic evidence shows some recited techniques were nascent/nonroutine in 2009 and that the particular combination was not routine | The patent’s written description is unambiguous that the techniques are conventional and binds the patentee; extrinsic evidence cannot contradict that public record | Held: The court treats the specification as binding; extrinsic evidence cannot overcome an unambiguous admission in the patent |
| Procedural: Whether the court could reconsider its earlier denial of summary judgment and resolve disputed facts sua sponte | CareDx contended factual disputes existed and summary judgment denial was proper | Court concluded it had authority under Rule 56(f)(3) and Third Circuit precedent to reconsider, identify undisputed material facts, hold an evidentiary hearing, and decide as a matter of law | Held: Court properly reconsidered, held a hearing, found no genuine material fact disputes, and entered summary judgment for defendants |
Key Cases Cited
- Alice Corp. Pty. v. CLS Bank Int'l, 573 U.S. 208 (framework for determining patent‑eligible subject matter under the two‑step Alice/Mayo test)
- Mayo Collaborative Servs. v. Prometheus Labs., Inc., 566 U.S. 66 (claims that apply a natural law using only well‑understood, routine, conventional activity are ineligible)
- Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir.) (affirming § 101 invalidity for detection claims where preparation/amplification were well understood and conventional)
- Athena Diagnostics, Inc. v. Mayo Collaborative Servs., 927 F.3d 1333 (Fed. Cir.) (method‑of‑detection claims are directed to a natural law when they recite only the law plus standard techniques)
- Cleveland Clinic Found. v. True Health Diagnostics LLC, 859 F.3d 1352 (Fed. Cir.) (method‑of‑detection claims invalid where claims use known testing methods with no meaningful non‑routine steps)
- Berkheimer v. HP Inc., 881 F.3d 1360 (Fed. Cir.) (step‑two inventive‑concept inquiry turns on whether claim limitations are well‑understood, routine, conventional activities)
- Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576 (Fed. Cir.) (when the public record unambiguously describes the invention, extrinsic evidence is improper to alter that record)
- Aatrix Software, Inc. v. Green Shades Software, Inc., 890 F.3d 1354 (Fed. Cir.) (noting difficulty for patentees to create genuine disputes when the specification admits conventionality)