The Supreme Court decisions in Mayo Collaborative Services v Prometheus Laboratories Inc. (2012) Ass’n for Molecular Pathology v Myriad Genetics Inc. (2013) altered the scope of patentable subject matter by redefining patent eligible subject matter. While isolated DNA and methods of diagnosis remain patentable in most of the world, in the United States, the scope of such claims, which contributed to the success of biotechnology companies, has been limited.
In Mayo, the Supreme Court held that a method for dosing a medication based on a patient’s metabolite levels after drug administration involves an application of a “law of nature.” In Myriad, the court held that an isolated genomic DNA molecule is not patent eligible; whereas cDNA, a copy of the encoded RNA, is patentable subject matter. The court held that claims to the BRCA1 and BRCA2 genes, which encode tumor suppressor proteins, encompass natural products, and, thus, are invalid because they encompass subject matter not eligible for patent protection.
Following the decision in Myriad, Myriad Genetics Inc. sued Ambry Genetics for infringement of patents that include claims to primers and methods of diagnosis by detecting mutations in the BRCA1 and BRCA2 genes using the primers. The Federal Circuit, in a decision that lacks scientific rigor, held that claims to the primers are ineligible for patent protection because the single-stranded DNA primers do not have a unique structure different from the DNA in nature. The court reasoned that, while single-stranded primers do not occur in humans, in accord with the decision in Myriad, isolation of DNA from other genetic material does not confer patent eligibility.
The method claims were directed to using the primers to compare a test subject’s DNA with wild-type DNA as a reference. The method claims did not recite a diagnosis of any particular disease nor identify any particular mutations. The court stated that comparison of the subject’s DNA with the reference DNA is merely a recitation of “abstract mental steps necessary to compare two nucleotide sequences,” which is patent ineligible. Subsequent steps recited in the claims were deemed routine and conventional. The method claims were held to be patent ineligible.
Because the method claims did not recite identification of any particular mutations nor steps of diagnosing or predicting a risk of developing a particular tumor, the decision does not address whether recitation of specific mutations or specific tumors would render claims patent eligible. Recitation identification of specific mutations that predispose the subject to developing a particular tumor may confer patent eligibility.
Applicants and patent practitioners should continue to file patents directed to methods of diagnosis and to isolated DNA. Many applications are filed worldwide, and isolated genes remain patentable everywhere else. Patent applications should include descriptions of differences in structure and function of the DNA from its structure and function in nature. Methods should include specifics, such as specific mutations detected, the disease diagnosed, particulars of the subject tested and anything that renders the test more than a recitation of abstract mental steps.