The U.S. Supreme Court is currently hearing a case on the validity of the isolated DNA and cDNA patents filed on BRCA1 and BRCA2 human genes used for diagnosing breast and ovarian cancers. The Association for Molecular Pathology has petitioned the Supreme Court to invalidate the patents held jointly by the Utah-based Myriad Genetics and the University of Utah Research Foundation.

Jacob S. Sherkow, Fellow at the Center for Law and the Biosciences, Stanford Law School explained to R. Prasad by email the intricacies of the case. Excerpts:

When you mention “composition claims” of the patent, do you mean patenting genes as a whole or just the isolated DNA?

When patent lawyers speak of “composition claims,” they're referring to claims directed at things, like a chair or a chemical molecule, as opposed to methods or systems of doing things. So, when I speak of the composition claims at issue in the Myriad case, I'm referring to two compositions: claims directed to “isolated DNA,” (small portions of DNA directly cut out of the human genome), and cDNA, or complementary DNA from mRNA transcripts.

Myriad Genetics apparently has three patents for cDNA-related work. Are they still valid? What are their expiry dates?

So, I think you're essentially seeking answers for two questions: A) whether the patents are valid, and B) whether they've expired.

A) Some of the claims of these patents have been declared invalid, first by the U.S. District Court for the Southern District of New York, and then affirmed by the U.S. Court of Appeals for the Federal Circuit. They are primarily the method claims — the methods for analyzing BRCA sequences to determine cancer risk — and are not before the U.S. Supreme Court now. Because they are not before the Supreme Court, those claims will remain invalid regardless of the Court's ruling. This does not mean that the entire patents are invalid, however; only those claims. The issue before the Supreme Court is whether the “composition claims,” that is, the isolated DNA and cDNA claims, are valid. The lower federal court (U.S. District Court for the Southern District of New York) declared them invalid; the intermediate federal court (U.S. Court of Appeals for the Federal Circuit) reversed the lower court and declared them valid; and the Supreme Court is currently considering the issue. The Supreme Court's decision is expected sometime in mid- to late-June.

B) First, it's important to note that the company has many more patents than that. They originally obtained seven patents for their BRCA work. But for the three patents you mentioned, they all expire on February 12, 2016.

Even if the Supreme Court takes the line advocated by the Amicus Curiae for the United States that isolated DNA are products of nature and hence not patent-eligible, will the company still have a few valid patents?

Again, it's important to distinguish between individual claimsand the entire patent itself. All of Myriad's patents, as a whole, will remain invalid, but if the Supreme Court sides with the government then Myriad's claims for isolated DNA sequences will become invalid.

Is cDNA really not found in nature? For a protein to be produced, cDNA has to be produced at some stage. Your views.

This is actually not true; for a protein to be produced mRNA has to be produced at some stage, but mRNA and cDNA are not the same thing. cDNA is unquestionably not found in nature. It derives its name from “complementary DNA,” correctly suggesting that there must be human intervention (i.e., molecular cloning) to producing it. Nonetheless, this does not mean that cDNA is not remarkably similar to other products found in nature, namely, mRNA. In fact, cDNA is often designed — as it was in Myriad's patents — to perfectly mimic the mRNA transcript. But its chemical composition is ultimately different: it is made out of deoxyribonucleosides, rather than ribonucleosides.

But this is the issue the Supreme Court will have to wrestle with: Even though cDNA is not found in nature, is it so similar to another natural product that it should not be patentable?

Even if Myriad has made cDNA from mRNA, don't you think some human manipulation would have occurred and that cDNA produced does not occur in nature?

Again, it is beyond dispute that cDNA does not occur in nature. Human intervention is decidedly required. But this doesn't decide the matter. The question before the Court, rather, is whether cDNA is sosimilar to mRNA, it should be considered as if it occurred in nature, and therefore unpatentable.

Even if patents related to cDNA are upheld, will it be possible for other companies to offer similar tests but without violating the three patents?

This is a great question. Ultimately, the answer is almost certainly yes, for two reasons: First, as I mentioned, some of Myriad's method claims have been ruled invalid. Therefore, anyone wishing to provide tests using those methods should be free to do so.

Second, there is some legal scholarship suggesting that whole genome sequencing — where researchers analyze your entire genome rather than one gene — may not infringe Myriad's patents. So that may make it possible to offer these tests.

At the same time, just because companies can offer the tests doesn't mean they will. The fear of a lawsuit, even a baseless one, drives many business decisions here in the U.S. Time will tell. But I do believe that after this case — regardless of how it comes out — the BRCA testing market will become more open.

Even if the validity of cDNA is upheld, is it right to say that Myriad has lost its patents on BRCA1 and BRCA2 genetic test?

Nope. As I mentioned above, some of Myriad's method claims have been declared invalid and those claims are not before the Supreme Court. So, regardless as to how the Court comes out, anyone wishing to practice those method claims should be free to do so.

In your view, should Myriad's patents for isolated DNA and cDNA be invalidated? Since such a ruling would invalidate many gene patents granted in the past, will the Supreme Court take the middle ground and make cDNA alone patent-eligible?

It is my personal opinion that composition claims directed at isolated genomic DNA should not be patent eligible. As for composition claims directed at cDNA that are simply copies of mRNA transcripts, I think they should be eligible for patenting, but nonetheless not patentable under other portions of the U.S. statute, namely, nonobviousness. I think other cDNA claims will have to be reviewed on a case by case basis.

Were the Supreme Court to rule that Myriad's composition claims are invalid, it would indeed invalidate many past claims: the estimates range in the thousands.

I think the Supreme Court will ultimately side with the United States on this one, but it's really tough to say. An easy way of making a fool of one’s self is predicting what the Court will do.

Correction

The story has been corrected on May 23, 2013 for factual error