As the dust from the impact of the Australian Myriad decision begins to settle, now is the time to revisit what many have said regarding patent eligibility of cDNA, against what the final appeal Court actually said.

On the former, many reported that the Court considered cDNA to be patent ineligible. Without doubt, this reporting is correct insofar as the Court held that the relevant Myriad claims (which the Court held would include cDNA) were invalid for lack of patentable subject matter. But is it true to say that the Court held that cDNA molecules, whether containing naturally occurring nucleotide sequence or otherwise, are patent ineligible?

First a ‘primer’ on cDNA.

cDNA (“complementary DNA”; aka “composite DNA” per US Supreme Court) is generally a molecule that arises from reverse transcription of mRNA. Reverse transcription is generally a mechanism that requires human intervention. Other than in certain retroviral lifecycles, reverse transcription is not a naturally occurring phenomenon. The outcome is that cDNA – even cDNA that has a naturally occurring nucleotide sequence - is generally not found in nature. It is understood that the US Supreme Court appreciated this concept of artificiality in reaching a conclusion that cDNA may be patent eligible subject matter.

So where in the Australian High Court’s decision is there a discussion regarding the patent eligibility of cDNA molecules? Reading the decision you will find discussion on the point by the majority at paragraph 89, and in a minority judgement at paragraph 283. It seems to be a real stretch to interpret either discussion as a conclusion of the Court on the inherent patentability of cDNA molecules.

On the former, the majority stated:

“Used in that sense, the information stored in the sequence of nucleotides coding for the mutated or polymorphic BRCA1 polypeptide is the same information as that contained in the DNA of the person from which the nucleic acid was isolated. 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. That characteristic also attaches to cDNA, covered by the claims which is synthesised but replicates a naturally occurring sequence of exons.”

It is particularly important to note that the majority had come to the view that the claims for “An isolated nucleic acid….”, were in fact for mere information - nucleotide sequence information. Having arrived at this point, it is perhaps not surprising that the majority was then able to group cDNA with other nucleic acids within the claim as patent ineligible subject matter. That cDNA as a molecule does not exist in nature is irrelevant in circumstances where the Court has formed the view that the relevant claim is for information that does exist in nature, and that information “also attaches to cDNA”.

On the latter, the minority stated in a discussion on the consequences of invalidity of the Myriad claims:

“A claim must be valid across its whole scope. It was common ground that if claims 1-3 did not contain patentable subject matter, then those claims would not be saved where they extend to forms of nucleic acid that have been synthesised in the laboratory (cDNA).”

Put in other words, a claim that is invalid to the extent that it broadly covers patent ineligible subject matter is not saved from invalidity merely because more narrowly it covers patent eligible subject matter. This is hardly a new concept in patent law!

Relevantly, nowhere did the Court opine that, because of an observed biological function, any and all cDNA molecules are inherently patent ineligible. That being the case, there are good arguments – based on the artificiality of cDNA – that a claim that is properly construed as defining a molecule – and not information – should be held valid on the patentable subject matter ground. That being the case, Australia’s legal position regarding patent eligibility of cDNA is, contrary to reports, not inconsistent with that of Australia’s major trading partners including US and Europe.