In a special session at the 2013 AACC Annual Meeting about the Supreme Court ruling on gene patents, the American Civil Liberties Union (ACLU) lead counsel in the case, Sandra Park, JD, told attendees that the story of gene patents isn't over. While ACLU won a big victory when the court unanimously struck down Myriad Genetics' patents on the BRCA gene, Park predicted that the landmark ruling would lead to further battles over human gene-related patents. In particular, she focused on the somewhat confusing issue of patents on complementary DNA (cDNA), which the Supreme Court left standing.

In leaving these patents untouched, the court relied on the fact that cDNA is the product of a process that retains only the exons needed to translate the DNA into proteins. As such, the court decided that cDNA is patentable because it is synthetic and not "naturally occurring" in the way other isolated DNA sequences are. After the court ruled, many companies—Myriad included—saw a victory in this part of the ruling. Patents for cDNA were safe.

But according to Park, the story is about to change again, and it may be only a matter of time before cDNA patents fall as well, affecting diagnostic firms that rely on these patents for their commercial success. "The court said that cDNA is not a product of nature, but clearly left open whether patents on cDNA might be invalid based on other grounds under the patent act," Park emphasized. "For example, the courts said that 'we express no opinion on whether cDNA satisfies the other statutory requirements of patentability.'"

One of the grounds of patentability that has been discussed as a possible way to invalidate patents on cDNA is called obviousness, Park explained. In patent law, obviousness refers to whether something is obvious based on what has been previously invented or published, and whether someone with ordinary skill in the relevant art or discipline would readily conceive of the innovation in question.

How obvious is cDNA?

The fate of cDNA could depend on how the courts interpret an earlier, unrelated case that examined cDNA, according to Park. In this 2009 case, "In re Kubin," the U.S. Court of Appeals for the Federal Circuit invalidated a patent based on cDNA on the grounds of obviousness. The patent claim covered cDNA that encoded a protein known as a Natural Killer Cell Activation Inducing Ligand (NAIL). The court found that because the protein was already known, the cDNA sequence was obvious. Even though this particular NAIL DNA sequence had not yet been published, the court cited the fact that someone of ordinary skill in molecular biology could use existing methods to obtain that sequence without difficulty.

Park noted that the Supreme Court has taken three patent-related cases since 2010, an unusual move for the court. Both in the decisions it has handed down, and in the language it has used, the justices have worked to establish a clear precedent that raises the bar for patents in biology, medicine, and business. "The Supreme Court has signaled that they are really concerned that there are too many patents that are potentially inhibiting scientific innovation," she said. "They clearly see both the appeals courts as well as the patent office as having been too loose in granting patents."