In the latest decision concerning diagnostic method claims a US Court1 has provided some guidance to the diagnostics industry on the interpretation of the recent Supreme Court decisions in Mayo v Prometheus2(Mayo) and AMP v. Myriad3(Myriad). In applying the test from Mayo, the Court invalidated a patent on the basis that the claimed subject matter was not patent eligible. To confirm its decision, the Court then asked whether the particular method claims in question would pre-empt all future use of the natural phenomenon to which the claims relate. All future uses were found to be pre-empted as there was no practical and commercially viable alternative methods to those claimed.
Sequenom is the exclusive licensee of US patent no. 6,258,540 (’540) that issued to Isis Innovation Limited. The ‘540 patent was based on the discovery in the mid 1990’s that cell-free fetal DNA (cffDNA) could be detected in maternal serum or plasma samples and describes methods of non-invasive detection of cffDNA in maternal serum or plasma samples to determine the presence of a paternally inherited nucleic acid of fetal origin.
A representative claim of the patent in issue is as follows:
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.
Applying the Mayo patent eligibility test
The Court assessed each claim to consider whether each would meet the requirements set forth in Mayo as follows:
- Is the claim a method / process claim (i.e. a claim with a series of steps)?;
- Does the claim recite a patent ineligible concept (i.e. law of nature, mental process, natural phenomenon, abstract idea) that is a limiting feature of the claim?; and
- Does the claim include additional elements or steps that are sufficient to ensure that the claim amounts to significantly more that the ineligible concept itself?
The Court held that the claims recited a natural phenomenon which is the presence of paternally inherited cffDNA in maternal plasma or serum. Therefore, the central issue was whether the claim included additional elements or steps that would be sufficient to ensure that the claim amounts to significantly more than the ineligible concept itself. The Court referred to the Mayo decision and re-iterated that a process claim would fail this step if the other elements were “nothing more than well-understood, routine, conventional activity previously engaged by researchers in the field”. Inventive or innovative use of the relevant phenomenon would be required.
The Court held that the amplifying and detecting steps were well-known and routine activity and pointed to statements in the specification that the preparation of serum or plasma from the maternal blood sample can be carried out by “standard techniques” and that “standard” nucleic acid amplification can be used. The Court also pointed to comments made during prosecution by the inventors that any well-known techniques for detection of DNA could be used to detect fetal DNA in maternal serum or plasma. A similar issue arose in PerkinElmer, Inc. v Intema Limited4 a discussion of which can be found at Protection of diagnostic inventions in the USA - implications of PerkinElmer, Inc. v Intema Limited.
Pre-empting all future uses
The Court then considered whether the claims in the ‘540 patent pre-empted all other uses of cffDNA, i.e. whether the claims would cover all future uses of cffDNA.
In response Sequenom provided articles that allegedly evidenced that alternative methods of using cffDNA existed. However, the Court held that the alternative methods were not commercially viable and therefore they were not evidence that all future uses of cffDNA would not be stopped by the patent. Supporting this conclusion, the Court noted that the evidence provided by Sequenom of alternative methods was from articles published well after the date of invention and the date the patent issued.
Lessons for Australian applicants
The interpretation of Mayo and Myriad in this latest decision appears to suggest the following:
- A claimed invention is not necessarily patent eligible because it relates to a use of a natural phenomenon;
- To be a patent eligible use of a natural phenomenon it must be an inventive or innovative use;
- An inventive or innovative use of a natural phenomenon will not arise from applying known technology / activity to the discovery of the natural phenomenon;
- It is critical that the use of the natural phenomenon does not pre-empt all future practical uses of natural phenomenon;
- Practical uses are commercially viable uses; and
- Claims cover the only commercially viable way of applying a natural phenomenon carry a higher risk of ineligibility for pre-emption.