(CN) - The Supreme Court on Tuesday refused to let a medical lab patent a dosage test it created for autoimmune disease treatments.
In a unanimous 24-page decision, the high court came to the same conclusion as a federal judge in the Southern District of California at the start of this litigation.
To determine the correct dosage of thiopurine drugs used to treat autoimmune diseases, the Mayo Clinic had long used tests patented by Prometheus Laboratories. But in 2005 Mayo began selling its own dosage test, prompting Prometheus to sue for patent infringement.
Mayo's argument that natural phenomena cannot be patented ultimately persuaded the District Court. Doctors look at a patient's metabolite levels to monitor the drugs' efficacy, not the Prometheus method, according to the decision.
On appeal, Prometheus argued that such interpretations of therapeutic and diagnostic methods would likely have a chilling effect on future medical discovery.
The Federal Circuit sided with Prometheus in 2009, finding that Prometheus transformed an unpatentable law of nature into a patent-eligible "application" of such a law.
Prometheus' expert, Dr. Yves Théoret, had testified: "At the end of the process, the human blood sample is no longer human blood; human tissue is no longer human tissue."
The Supreme Court diminished the importance of that test, however, in 2010 with Bilski v. Kappos, which found that the some systems are too obtuse to be patented. The decision called the machine-or-transformation test "a useful and important clue," but not the sole test for determining the patent eligibility of process claims.
Later that year when Mayo petitioned for review of the Prometheus decision, the high court vacated the Federal Circuit's ruling and directed the appellate judges to reconsider the case in light of Bilski.
On remand, however, the Federal Circuit did not waver from its earlier finding.
After taking up the case in June, the high court proved Tuesday that it meant business.
Precedential cases "warn us against interpreting patent statutes in ways that make patent eligibility 'depend simply on the draftsman's art' without reference to the 'principles underlying the prohibition against patents for [natural laws],'" Judge Stephen Breyer wrote for the court. "They warn us against upholding patents that claim processes that too broadly preempt the use of a natural law. And they insist that a process that focuses upon the use of a natural law also contain other elements or a combination of elements, sometimes referred to as an 'inventive concept,' sufficient to ensure that the patent in practice amounts to significantly more than a patent upon the natural law itself."
"We find that the process claims at issue here do not satisfy these conditions," Breyer added. "In particular, the steps in the claimed processes (apart from the natural laws themselves) involve well-understood, routine, conventional activity previously engaged in by researchers in the field. At the same time, upholding the patents would risk disproportionately tying up the use of the underlying natural laws, inhibiting their use in the making of further discoveries."
The justices rejected Prometheus' claim that its tests were patentworthy because they concern a narrow and specific area.
"A patent upon a narrow law of nature may not inhibit future research as seriously as would a patent upon Einstein's law of relativity, but the creative value of the discovery is also considerably smaller," Breyer wrote. "And, as we have previously pointed out, even a narrow law of nature (such as the one before us) can inhibit future research."
In an amicus brief, the U.S. government argued for a low threshold for the transformation of a law of nature into a potentially patentable application. But the justices called said this argument would turn the law-of-nature exception into "a dead letter."
As to Prometheus' fears of a chilling effect, the justices pointed out that the fears go both ways. A series of medical organizations wrote in their amicus brief that letting Prometheus' patents stand would create "a vast thicket of exclusive rights over the use of critical scientific data that must remain widely available if physicians are to provide sound medical care.'"
"We do not find this kind of difference of opinion surprising," Breyer wrote. "Patent protection is, after all, a two-edged sword. On the one hand, the promise of exclusive rights provides monetary incentives that lead to creation, invention, and discovery. On the other hand, that very exclusivity can impede the flow of information that might permit, indeed spur, invention, by, for example, raising the price of using the patented ideas once created, requiring potential users to conduct costly and time-consuming searches of existing patents and pending patent applications, and requiring the negotiation of complex licensing arrangements."
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