In the Prometheus case in early 2012, the Supreme Court struck down two patents covering a method for using blood tests to determine the dosage of thiopurines, which are used to treat gastrointestinal problems. The Court ruled that the patents are based on a law of nature and are therefore not patentable. The implications of that ruling could be considerable. “It is clear that personalized medicine and diagnostics could be significantly affected by the Prometheus decision, based on decisions regarding patents in similar fields,” says Matt Becker, co-chair of Axinn, Veltrop & Harkrider LLP’s intellectual property practice.

Shortly after the Prometheus ruling, the Supreme Court remanded a different patent case, Association for Molecular Pathology v. Myriad Genetics, to the Court of Appeals for the Federal Circuit. In August 2012, that court reaffirmed the patents of two genes associated with breast and ovarian cancer, while denying the company’s patent methods used to analyze DNA sequences. Following that, the Supreme Court decided to revisit the Myriad case to establish whether human genes are patentable subject matter. The decision should shed light on the distinction between inventions and natural phenomena. Going forward, the Myriad and Prometheus cases are poised to be important for the burgeoning field of personalized medicine.

For instance, on November 20, 2012, the Federal Circuit issued a decision in PerkinElmer, Inc. v. Intema Ltd. using Prometheus to invalidate patents. “The patents at issue were for methods of determining whether a pregnant woman is at increased risk of having a fetus with Down’s syndrome,” Becker says. The patents involved conducting two screening tests using separate markers at separate times in the pregnancy. The tests combine the measured levels to determine risk by comparison of the measured levels with known frequency distributions in affected and unaffected pregnancies, Becker explains. “The court found relevant that the claims did not require the doctor to act on the calculated risk. The court also noted that the Myriad decision supported the outcome because the patentability in Myriad came from the use of host cells that did not occur naturally, whereas the diagnostic method in that case did not involve any patent-eligible application of the law of nature. The court also found that the claims failed the ‘machine or transformation’ test.”

The ruling in another case on March 30, 2012, SmartGene, Inc. v. Advanced Biological Labs, SA, also invalidated a patent covering a method for selecting a treatment regimen for patients with a known disease or medical condition. Specifically, the patent covered the use of a computing device to rank therapeutic treatments based on inputted patient information. In SmartGene, the court in the District of Washington D.C. found that the claimed methods “do no more than describe just an abstract mental process engaged in routinely, either entirely within a physician’s mind, or potentially aided by other resources in the treatment of patients.” In addition, the court found the claims failed the “machine-or-transformation” test.

Becker also points to Aria Diagnostics, Inc. v. Sequenom, Inc., a case in the Northern District of California, which denied a preliminary injunction in part because the accused infringer raised a substantial question as to validity of the patents under Prometheus. “The patent was to a method of using cell-free fetal DNA in the blood of a pregnant woman to conduct non-invasive prenatal testing,” Becker explains. “The defendant argued that all the patent claimed was the discovery that fetal DNA naturally exists in the mother’s blood, combined with conventional techniques of amplifying and detecting that DNA,” he says. “The court rejected the patentee’s argument that the claims ‘recite specific steps that confine the claims to a specific, useful application’ because the evidence showed that the techniques used were standard. That opinion was issued July 5, 2012.

A notable post-Prometheus medical case that did not apply Prometheus to render claims ineligible is Classen Immunotherapies, Inc. v. Biogen IDEC. In that case, Judge Zito in the District of Maryland denied a motion to dismiss based on Prometheus, Becker explains. “The patent [covered] a method of choosing an immunization schedule for infants to minimize the likelihood of developing chronic immune mediated disorders or common infectious diseases,” he says. “The court relied on an earlier Federal Circuit decision on the patents, which stated that the physical step of immunization on a determined schedule rendered the claims patentable, to find that the claims could not be dismissed under Prometheus.” In a decision issued August 9, 2012, the court observed that there was, at that time, no information in the record that allowed it to conclude that the claims involved only routine or conventional activity, Becker explains. “The court went further to suggest that the claims are safe under Prometheus specifically because they required immunizing according to a particular schedule in addition to data-gathering,” he says. “It is unclear whether the court viewed its opinion as deciding the Prometheus issue permanently, or just at that stage of the litigation, where no record had been developed, and whether the claims would be patentable if the concrete step of requiring immunization was later shown to be conventional or routine.”

 Brian Buntz is the editor-at-large at UBM Canon's medical group. Follow him on Twitter at @brian_buntz.