Federal Circuit Invalidates Diagnostic Testing Patent Claims

The limits of what can be patented in the life sciences continue to be refined by this period of active litigation in which foundational questions over patentable subject matter - 35 U.S.C. 101 - are receiving judicial attention. The Federal Circuit has just expanded on its jurisprudence for the patent eligibility of diagnostic testing methods which utilize either biochemical or genetic markers to determine the clinical status of an individual. In Perkin-Elmer, Inc. v. Intema Limited, the court invalidated patent method claims which relied on a series of prenatal measurements of known biological markers, performed through blood testing or ultrasound, to determine whether a woman has an elevated risk of carrying a fetus with Down’s syndrome. In Mayo v. Prometheus, decided earlier this year, the Supreme Court invalidated a patent claim to a method of optimizing drug dosing because the claim did no more than capture a natural biological correlation. Patent law doctrine does not allow the patenting of laws of nature, natural phenomena or abstract ideas. Yet, deciding whether a patent claim adds inventive weight to natural subject matter is not a simple test. The courts have often focused on whether a patent claim would actually "preempt" the use of a natural biological fact or phenomena if it were to issue. Would the patent holder effectively capture uninvented scientific information? This question has also been considered in the gene patent case, Association for Molecular Pathology (AMP) v. PTO, where the Federal Circuit invalidated method claims which did no more than use the fact that certain DNA mutations are correlated with elevated breast cancer risk. In Perkin-Elmer, referencing AMP, the court said that "the stricken claims there are indistinguishable from those before us." Further, the court stated that " Intema also claims a law of nature: the relationship between screening marker levels and the risk of fetal Down’s syndrome." With reference to the invalidated claims in AMP, the Perkin-Elmer court stated that "the stricken claims there are indistinguishable from those before us."The lineage of this decision is clear: “The Supreme Court’s decision in Mayo and this court’s recent decision in [AMP] dictate the result we reach today.” This case thus builds on the Mayo and Myriad framework for the analysis of method claims in the life sciences that are anchored in the recitation of a law of nature or natural correlation. In a reference to the possibility that the patent claims impermissibly preempt, the court stated that "anyone who wants to use this mental step or natural law must follow the claimed process." Thus, valid method claims in the diagnostic arts require more customized treatments of natural subject matter in order to qualify as an “inventive concept” and to avoid preemption over basic scientific subject matter. Further to the march of patentable subject matter cases through the courts, we await the Supreme Court's decision on the plaintiffs' petition for certiorari filed in AMP v. USPTO; the petition is scheduled for the Court’s conference tomorrow.