The patent-eligibility of medical diagnostics in Australia remains unchanged following a recent decision of the Federal Court in Sequenom v Ariosa[i]. While this decision does not change patent eligibility in Australia, it does demonstrate a decisive divergence between Australian and US courts when considering what constitutes a patentable invention.

As we have previously reported, in 2015 the High Court of Australia in D’Arcy v Myriad Genetics (Myriad)[ii] followed the lead set by the United States two-years earlier and ruled that inventions directed to isolated nucleic acids – so called “gene patents” – were not eligible to be patented. Since the decision in Myriad, it has been speculated that Australia may also follow the United States’ lead and limit patent-eligibility for medical diagnostic inventions. However, the recent decision in Sequenom v Ariosa confirms that this is not the case.

Medical Diagnostic Patents in the US – A Brief History

In 2012, the US Supreme Court ruled in a case between Mayo Collaborative Services and Prometheus Laboratories Inc. (Mayo) that a patent relating to a method of optimising the efficacy of a treatment was not valid[iii]. The basis for the decision in Mayo was that the claims in question essentially covered a natural phenomenon, and the additional ‘well known’ features to the claims did not amount to anything significantly more than the natural phenomenon.

The Mayo decision immediately impacted the prosecution of life sciences related patents in the United States, particularly those concerning medical diagnostics. The rejection rate of medical diagnostic applications in the United States – on the basis that they were directed to non-patent eligible subject matter – increased from 7% to 35% in the month after the decision. In subsequent years, the rejection rate further increased to 64%[iv]. The decision in Mayo was also quickly applied by the lower courts in the United States. One of the early applications of Mayo was in relation to a patent directed to non-invasive prenatal genetic testing, which was licensed by Sequenom Inc.

Prenatal Testing – A Test of Patent-Eligibility

Traditional prenatal genetic screening involves invasive amniocentesis, cordocentesis or chorionic villus sampling whereby needle biopsies of amniotic fluid, cord blood or the chorionic villi of the placenta are taken during pregnancy. In 1998 it was first reported that cell-free fetal DNA circulated in the mother’s blood stream and that this DNA may be useful in non-invasive prenatal diagnostics[v]. This finding became the basis of the US patent 6,258,540 and the Australia patent 727919 (amongst others), that were ultimately licensed to Sequenom.

Specifically, the first claim in US patent 6,258,540 recited:

A method for detecting a paternally inherited nucleic acid of fetal origin performed on a maternal serum or plasma sample from a pregnant female, which method comprises: 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.

In comparison, the first claim of the Australian patent 727919 recited:

A detection method performed on a maternal serum or plasma sample from a pregnant female, which method comprises detecting the presence of a nucleic acid of foetal origin in the sample.

Ariosa entered the market in the United States in 2012 with a non-invasive prenatal test marketed under the name Harmony™. This test was in competition with Sequenom’s MaterniT21™ test which had entered the market in 2011. The Harmony™ test was subsequently licensed into Australia in 2015.

In 2013 the District Court for the Northern District of California[vi] considered if Ariosa’s Harmony™ test infringed Sequenom’s licensed US patent. This was further considered by the Federal Circuit Court in 2015[vii]. Ultimately, it was determined that in view of the test set forth in Mayo, the claims of Sequenom’s patent were not directed to patent-eligible subject matter, and consequently the claims were not enforceable. In arriving at this decision the Court considered that the claims failed to encompass substantially more than a natural phenomenon, being the existence of cell-free fetal DNA in maternal blood.

Sequenom v Ariosa in Australia

In 2016, Sequenom commenced proceedings in the Federal Court of Australia alleging infringement of their Australian patent by Ariosa and its Australian licensees, while Ariosa cross-claimed for invalidity of the patent on several grounds, including that the claims were not directed to patent eligible subject matter.

In assessing if the claims in Sequenom’s Australian patent were directed to patent eligible subject matter the Court considered Myriad which directed analysis of what forms the “substance” of the claim. In essence the Court was asked to consider if the substance of the claims in Sequenom’s Australian patent was merely the discovery of a natural phenomenon, being the existence of fetal nucleic acids in the maternal circulatory system. Further, it was put to the Court that the claims merely resulted in information only and there was no ‘artificially created state of affairs’[viii], which has been a cornerstone of determining patent eligible subject matter since the NRDC decision in 1952[ix].

This argument was comparable to that affirmed in the equivalent litigation in the United States. In other words, Ariosa argued that due to the harmonious position taken between the Australian and the United States’ highest courts with regard to Myriad, Australia should similarly adopt the position of the US with regard to the diagnostic claims in Sequenom’s Australian patent[x].

Ultimately, the Court rejected Ariosa’s arguments, and determined that the detection of cell-free fetal DNA inherently involved human interaction and was therefore an ‘artificially created state of affairs’[xi]. The court concluded that Sequenom’s patent claimed a new and inventive application of the discovery of cell-free fetal DNA, and required human action to detect a DNA sequence of fetal, rather than maternal, origin.