By now most will know that:

  1. Australia’s final appeal Court has made adverse findings against Myriad’s patent for utilising the BRCA1 locus to diagnose breast cancer;
  2. the rejected claims are only those that define isolated nucleic acids; and
  3. the various obiter statements indicate that claims defining diagnostic methods are not inherently patent ineligible.

So what aspect of a diagnostic assay was rejected by the High Court? What is no longer patent eligible? And is the rejection confined to nucleic acids utilised in diagnostic assays? Or are serological or antibody based assays now implicated? Perhaps it is useful to consider the key components of a diagnostic assay before we seek to answer these questions!

All diagnostic tests are based on the following precepts:

  1. an established association between a condition or trait and a biomarker (a biomarker being a measurable indicator of the condition or trait);  
  2. a method for practice on an individual in whom the presence of the condition or trait is to be determined;
  3. a detection means utilised in the method for directly or indirectly interacting with the biomarker;
  4. a signal containing information as to whether an interaction between the biomarker and the detection means has occurred, thereby determining presence or absence of the biomarker, and by implication, presence or absence of the condition or trait.

Relevantly, in many diagnostic assays, the signal at (iv) is, or arises from a molecular species that is produced by the method at (ii) as a result of the interaction, or lack of interaction of the detection means at (iii) with the biomarker. For example, where the detection means is a nucleic acid probe, the signal may be a duplex formed from a biomarker in the individual in the form of a nucleic acid, and the probe.

From a patent perspective it is clear that at least two of these precepts refer to patent eligible subject matter. First, a patent eligible ‘process’; namely the method  at (ii). Second a patent eligible ‘product’; namely the detection means at (iii). (While not yet decided in Australia, there is some doubt as to whether the precept at (i) by itself refers to patent eligible subject matter, although that was not decided in this case and is a topic for separate discussion).

But what about the molecular species that forms the signal at (iv); the thing that is ostensibly produced by the method at (ii). If you consider the method at (ii) to be a patent eligible method of making a molecular species, isn’t the molecular species a patent eligible product, irrespective of whether it functions as a signal?

This appears to be the very question put before the High Court. Specifically, isn’t the claimed ‘isolated nucleic acid coding for a mutant or polymorphic BRCA1 polypeptide’ and having any one or more mutations as relevantly claimed, a patent eligible product?

Myriad had argued that the claim language expressly defined a product in the form of a chemical compound. On that basis the claim was said to define patent eligible subject matter, irrespective of what the substantive function of the claimed isolated nucleic acid was alleged to be.

But the High Court did not agree with Myriad’s submission.  The substance of the claim was considered to be information: “It is the existence of that information which is an essential element of the invention as claimed. The product is the medium in which that information resides.” One wonders, whether in coming to this view, the Court recognised the relevant claim as encompassing a mere signal as per (iv) above – something that communicates patient specific information or data in the form of nucleotide sequence information on the likelihood of cancer.

So to answer the first question, namely, ‘what aspect of a diagnostic assay was rejected by the High Court?’, it seems that the High Court has rejected the notion that information (i.e a signal) arising from implementation of the diagnostic method is patent eligible – and it has done so even where one has attempted to lay claim to that signal as a product. In the words of the Court, it is improper to “elevate form over substance”.

Turning to the second question, ‘what is no longer patent eligible?’ in these circumstances you have to wonder whether the decision has considered a concept of subject matter beyond those previously considered in earlier judgements. In particular, prior to the decision, did anyone really accept that information or data or test results are patentable subject matter? In this context, the decision seems to merely confirm conventional understanding of eligibility of subject matter for patent protection. (Perhaps if there is something ‘new’ about the decision, it is the Court’s interpretation of a patent claim that prima facie was generally understood to define a compound per se).

Of more interest is the question ‘are serological or antibody based assays now implicated?’ For example, where the detection means is an antibody and the signal is a molecular species in the form of an immune complex, would a claim to the immune complex be considered patent eligible subject matter?

Clearly from the decision, the question requires one to consider ‘substance’ of invention together with ‘form’ of claim language. The answer would seem to turn on whether the substance of the claimed ‘product’ i.e. the immune complex, is nothing more than “the medium in which that information [the ‘signal’] resides”. There is a strong argument that in the relevant circumstances, such a claim would be considered to cover patent ineligible subject matter.  In this context, the Myriad decision would reach beyond claims to isolated nucleic acids and it is likely that it would extend to all claims to a molecular species that forms a signal as at (iv) above, if it is found that the molecular species is nothing more than a medium in which relevant information – presence or absence of biomarker, or condition or trait – resides. Clearly this is not to rule out a detection means per (iii) from patent eligibility.

So what impact will the Australian Myriad decision have on patent eligibility of diagnostic tests? In our view – no impact, provided that the patent claims are limited to a method at (ii) or the detection means at (iii). There should be no impact provided that the patent claims do not cover the signal – whether that be a nucleic acid, immune complex, dyed target or otherwise – that is formed by the implementation of the detection means at (i) in the method at (ii).