Hands Tied: Patenting Diagnostic Inventions Remains a Difficult Task

Blogs, Patent 213

Author(s) Kimberly Vines, Ph.D.

Patent 213 Blog

Hands Tied: Patenting Diagnostic Inventions Remain a Difficult TaskWhat does the Federal Circuit really think about the Supreme Court’s recent § 101 jurisprudence? The denial of the petition for rehearing en banc in Ariosa Diagnostics v. Sequenom in November of 2015 answers that question. The 30-page panel opinion in the denial of the petition for rehearing en banc can be boiled down to just a few words: “Our hands were tied and it’s up to the U.S. Supreme Court to fix this.” Earlier last year, the Federal Circuit affirmed the district court’s grant of summaryjudgment of invalidity of Sequenom’s claims in US 6,258,540 (‘540). The claims at issue were directed to a method for detecting paternally inherited cell-free fetal DNA (cffDNA) performed on maternal plasma or serum, the method comprising amplifying a paternally inherited nucleic acid from the serum or plasma sample, and detecting the presence of a paternally inherited nucleic acid of fetal origin in the sample. Although this method revolutionized prenatal care, as noted in Myriad and restated in Ariosa, “[g]roundbreaking, innovative, or even brilliant discovery does not by itself satisfy the § 101 inquiry.”

Judge Lourie wrote:

 [I]t is undisputed that before this invention, the amplification and detection of cffDNA from maternal blood, and use of these methods for prenatal diagnosis, were not routine and conventional. But applying Mayo, we are unfortunately obliged to divorce the additional steps from the asserted natural phenomenon to arrive at a conclusion that they add nothing innovative to the process.

It is important to define what qualifies as a law of nature, natural phenomenon, or a product of nature for biotechnology inventions because it is the first step of the Mayo test. There has been longstanding case law against patenting laws of nature, but there was also a significant loophole—that an isolated and purified product of nature was patent eligible if the isolated product had improved utility when compared to the product in its natural state. Until recently, claims to isolated DNA were considered patentable subject matter because isolated DNA fell within the “isolated and purified” exception to the product of nature doctrine.

The Myriad decision ushered in a sea-change in patent law for biotechnology inventions under the product of nature exception. Indeed, never before had an appellate court invalidated a claim covering a molecule, including a DNA molecule, under the product of nature doctrine. The claims in Myriad included composition claims to both the genomic DNA (gDNA) and the complementary DNA (cDNA) sequences of the genes associated with the development of breast and ovarian cancer (BRCA1 and BRCA2). The Court invalidated the claims directed to gDNA as directed to patent ineligible subject matter, but upheld the claims directed to cDNA. The gDNA claims were held invalid because Myriad did not create or alter the genetic information encoded in the BRCA1 and BRCA2 genes. The claims directed to cDNA were held valid because cDNA was not a product of nature; DNA in the body does not exist as only coding regions with the non-coding regions excised from the sequence as it does in cDNA.

In effect, the Myriad Court rejected the “purified and isolated” exception as applied to DNA-based inventions: “genes and the information they encode are not patent eligible under § 101 simply because they have been isolated from the surrounding genetic material.”  Rather, the Court adopted the “markedly different characteristics” approach of Chakrabarty. The Court recognized that there were structural differences between the isolated gDNA and chromosomal DNA, but rejected those differences as enough to save the claims because the claims were “not expressed in terms of chemical composition, nor do they rely on the chemical changes resulting from the isolation of a particular DNA section.” The Court was persuaded by the DNA-as-information argument in the district court opinion concluding that gDNA was not markedly different from chromosomal DNA. The function of gDNA was the same as the function of chromosomal DNA—to provide a genetic code that contains information. By altering the “purified and isolated” exception as applied to biotechnology inventions, the Court radically expanded the scope of the product of nature doctrine. The practical result is that many more biotechnology inventions now fall within the product of nature exception.

Applying the Mayo test to the Ariosa case, the district court held that the claims at issue were invalid as directed to patent-ineligible subject matter. Prior to Myriad, because the cffDNA was isolated, this would have saved the claim from satisfying the first step of the Mayo test, but applying the new standard, the fact that the cffDNA was isolated from the surrounding genetic material does not remove it from the product of nature exception. Furthermore, according to the district court, the additional steps consisted of “well-understood, routine, conventional activity already engaged in by the scientific community.” The isolation of DNA, amplification of certain sequences, and detection (e.g., agarose gel electrophoresis) were found to be “conventional and routine” and failed to constitute an inventive concept as required in the Mayo test. The Federal Circuit affirmed, and the panel reluctantly denied the petition for rehearing en banc.

The results in Ariosa illustrate the challenges that face those seeking to patent protection for method claims in the life sciences. These claims are usually directed to newly discovered natural laws and phenomena that are applied using conventional and well-known techniques to create new and useful tests for diseases and risks of diseases. In the en banc opinion, some members of the panel agreed that the current test was too restrictive a test for patent eligibility under § 101, but they were bound by the language in Mayo. Until the U.S. Supreme Court decides to revisit this issue, the current Mayo framework will make patenting diagnostic inventions a difficult task.