40 F.4th 1371
Fed. Cir.2022Background
- Stanford owns U.S. Patents ’652, ’497, and ’607 claiming methods to detect and quantify donor-derived cell-free DNA (cfDNA) in transplant recipients to diagnose or predict organ rejection. Representative claims recite four core steps: obtaining a sample, genotyping donor/recipient SNP profiles, sequencing or digital PCR, and quantifying donor cfDNA.
- CareDx (exclusive licensee) sued Natera and Eurofins for infringement; defendants moved to dismiss or for summary judgment alleging the claims are patent-ineligible under 35 U.S.C. § 101.
- The district court initially denied summary judgment to allow fact development, but after discovery reconsidered and granted summary judgment, holding the claims directed to natural phenomena (donor cfDNA and its correlation with rejection) and that the claimed steps are conventional per the patents’ own specification.
- CareDx argued the inventive advance was improved measurement (use of digital PCR, NGS, selective amplification) rather than the natural correlation; defendants argued the claims merely apply conventional techniques to a natural phenomenon, making them indistinguishable from Mayo/Ariosa-type claims.
- The Federal Circuit affirmed: claims are directed to a natural phenomenon at Alice/Mayo step one and lack an inventive concept at step two because the specification expressly describes the recited techniques as conventional and the claimed combination adds nothing inventive.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether the asserted claims are "directed to" a natural law/phenomenon (Alice/Mayo step one) | CareDx: Claims are directed to improved, human-devised measurement methods for cfDNA, not the natural correlation itself. | Defendants: Claims recite detecting donor cfDNA and its correlation to rejection; specification admits techniques are conventional. | Held: Claims are directed to natural phenomena (donor cfDNA and its correlation with rejection). |
| Whether the claims contain an "inventive concept" (Alice/Mayo step two) | CareDx: Use of digital PCR, NGS, and selective amplification is an inventive application that transforms the natural phenomenon into patentable subject matter. | Defendants: Those techniques are standard/off‑the‑shelf; combining them is routine and non‑inventive. | Held: No inventive concept; the claims only recite conventional steps and a routine combination. |
| Whether factual disputes (expert evidence) precluded summary judgment | CareDx: Extrinsic evidence raised genuine issues of conventionality and credibility that should have precluded summary judgment. | Defendants: Intrinsic admissions in the specification contradicted extrinsic evidence, eliminating any genuine issue. | Held: District court properly reconsidered; intrinsic admissions defeated the factual dispute and summary judgment was appropriate. |
Key Cases Cited
- Diamond v. Chakrabarty, 447 U.S. 303 (Sup. Ct.) (broad scope of § 101 and "anything made by man" principle)
- Mayo Collaborative Servs. v. Prometheus Lab’ys, Inc., 566 U.S. 66 (Sup. Ct.) (laws of nature/natural phenomena excluded; two-step test; conventional steps cannot make law of nature patentable)
- Alice Corp. Pty. Ltd. v. CLS Bank Int’l, 573 U.S. 208 (Sup. Ct.) (framework for "directed to" and "inventive concept")
- Diamond v. Diehr, 450 U.S. 175 (Sup. Ct.) (applications of natural laws can be patentable)
- Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir.) (cfDNA diagnostic claims found ineligible; closely analogous precedent)
- Illumina, Inc. v. Ariosa Diagnostics, Inc., 952 F.3d 1367 (Fed. Cir.) (distinguishing claims that recite new preparation methods from those that merely detect natural phenomena)
- Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, 915 F.3d 743 (Fed. Cir.) (specification describing techniques as conventional supports ineligibility)
- Roche Molecular Sys., Inc. v. CEPHEID, 905 F.3d 1363 (Fed. Cir.) (standard PCR techniques appended to a natural phenomenon do not supply an inventive concept)
- Cleveland Clinic Found. v. True Health Diagnostics LLC, 859 F.3d 1352 (Fed. Cir.) (claims with no meaningful non‑routine steps are ineligible)
- Berkheimer v. HP Inc., 881 F.3d 1360 (Fed. Cir.) (patent eligibility can involve underlying factual disputes but intrinsic admissions can resolve them)
- SRI Int’l, Inc. v. Cisco Sys., Inc., 930 F.3d 1295 (Fed. Cir.) (standard of review for summary judgment in patent cases)
- Elec. Power Grp., LLC v. Alstom S.A., 830 F.3d 1350 (Fed. Cir.) (acknowledging overlap between Alice/Mayo steps and related scrutiny)