Background
Sequenom held patents on a groundbreaking discovery: that cell-free fetal DNA (cffDNA) — fetal DNA shed into the maternal bloodstream — could be detected in maternal blood samples, enabling non-invasive prenatal genetic testing without the risks of amniocentesis or chorionic villus sampling. Drs. Lo and Wainscoat discovered this natural phenomenon and patented methods of detecting paternally inherited cffDNA in maternal serum or plasma as a way to diagnose fetal genetic conditions. Sequenom commercialized this technology as its MaterniT21 test for detecting chromosomal abnormalities like Down syndrome.
Ariosa Diagnostics developed a competing non-invasive prenatal test (NIPT) and challenged Sequenom’s patent as invalid under § 101. The district court found the claims patent-ineligible and granted summary judgment of invalidity. Sequenom appealed.
The Court’s Holding
The Federal Circuit affirmed, 3-0 (with a concurrence expressing deep unease about the result). The court held that Sequenom’s claims were directed to a natural phenomenon — the presence of cffDNA in maternal blood — and that the method steps used to detect it (amplifying and detecting paternally inherited sequences using standard PCR and detection techniques) were conventional and routine in the molecular biology field. Under Mayo’s two-step framework, the conventional detection steps did not supply an inventive concept sufficient to transform the natural phenomenon into a patent-eligible application.
Judge Linn wrote a concurring opinion expressing reluctance with the result, arguing that the Mayo framework as applied by the court led to invalidating a genuinely groundbreaking discovery by treating the specific practical application of detecting cffDNA as indistinguishable from merely claiming the natural phenomenon itself. He criticized the Mayo framework as threatening to prevent patenting of important medical discoveries.
Key Takeaways
- Discovery of a previously unknown natural phenomenon (the presence of cffDNA in maternal blood) combined with using conventional detection techniques to detect it is patent-ineligible under § 101 — the natural phenomenon cannot be patented, and the detection steps must supply something inventive beyond conventional laboratory techniques.
- The most medically and commercially important diagnostic discoveries can still be patent-ineligible if the method of detecting the phenomenon uses only conventional, routine steps in the relevant scientific field — making “pioneering” discoveries in molecular diagnostics particularly vulnerable to § 101 challenges.
- Sequenom v. Ariosa became one of the most cited and criticized applications of the Mayo framework — illustrating tension between the § 101 doctrine and innovation incentives in molecular diagnostics, since the discovery itself was genuinely novel and enabled an entire field of non-invasive prenatal testing.
- Practitioners drafting diagnostic method patents after Ariosa need to claim specific non-conventional detection methods or specific technical implementations — not merely the application of standard laboratory techniques to detect a newly discovered natural phenomenon.
Why It Matters
Ariosa Diagnostics v. Sequenom was one of the most controversial patent eligibility decisions of the post-Mayo era — a case in which a genuinely pioneering discovery that enabled an entire clinical testing category (non-invasive prenatal testing) was found patent-ineligible because the detection method used conventional laboratory tools. The decision generated widespread criticism from the medical research community, patent practitioners, and even judges on the Federal Circuit who concurred while questioning whether the Mayo framework was well-calibrated for molecular diagnostics.
The ruling directly affected the commercial landscape for prenatal genetic testing: Sequenom lost its ability to use patents to protect its NIPT business, leading to rapid commoditization of the testing market. More broadly, Ariosa established a challenging precedent for molecular diagnostic patent protection — suggesting that even transformative discoveries about natural phenomena cannot be patented when the claimed detection method uses standard molecular biology tools. The case has been extensively discussed in the context of § 101 reform proposals arguing that the current framework discourages investment in diagnostic technology innovation.