Like the United States Supreme Court, the High Court of Australia has determined that Myriad's patents directed to purified and isolated DNA molecules encoding the BRCA genes are unpatentable. Indeed, the Australian Court went one step further than the U.S. Court, holding that non-naturally occurring cDNA molecules encoding the genes are also unpatentable.

This decision reverses decades of precedent that recognized the patentability of particular nucleic acid sequences that are isolated from nature and overturned a decision by the Full Federal Court of Australia that had confirmed the patentability of such molecules. The Full Federal Court had held that because the claimed BRCA gene molecules differed from naturally occurring counterparts both structurally and functionally as a result of their isolation, the claims were directed to patentable subject matter. The High Court, however, focused on the information encoded by the molecules, rather than functional and structural differences, and found that since the same information was contained in both the isolated genomic DNA and in cDNA that retained the relevant sequence of exons, neither constituted patentable subject matter.

In the U.S., the Supreme Court held that mere purification and/or isolation of a naturally occurring substance such as DNA is not enough to confer patentability, but that the substance must possess "markedly different characteristics" from the naturally occurring counterpart. The most recent guidance documents from the U.S. Patent and Trademark Office confirm that this test is being broadly applied to any substance derived from nature, not just DNA and other biologic molecules. Accordingly, patent practitioners and their clients are struggling to determine whether their innovative efforts to develop products that include a component derived from nature may be entitled to patent protection.

One may expect a similar result in Australia. Indeed, since the High Court found that structural differences between cDNA and its naturally occurring counterpart are insufficient to render the cDNA as patent-eligible subject matter, one must wonder how much structural modification would be sufficient. For example, would the use of recombinant technologies be enough to confer patentability to a protein that is also found in nature, even if the recombinant protein has different structural characteristics, such as a different glycosylation pattern or crystalline structure? Is a vaccine that relies on only a fragment of a naturally occurring antigen still patentable? These questions and many more like them await further answers from the Australian courts.

In the meantime, the High Court has called into the question the validity of literally thousands of issued Australian patents. The extent to which this uncertainty serves to chill investment in biotechnology and other industries in the country remains to be seen.

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