Prometheus Scores Win in Case Over Method Patents

(CN) - In a decision that could have a profound effect on the future of patent law for medical treatments, the Federal Circuit ruled that a test for determining the proper dosage of drugs to treat autoimmune disease is patentable under federal law.

A three-judge panel sent the patent dispute between Prometheus Laboratories and the Mayo Clinic's medical laboratory division back to a federal judge in Southern California, saying the judge incorrectly dismissed Prometheus' infringement claim against Mayo.

Mayo has long used Prometheus' patented test for determining the correct dosage of thiopurine drugs used to treat autoimmune diseases. In 2005 it announced that it would begin selling its own dosage test, prompting an infringement lawsuit from Prometheus.

Mayo argued that Prometheus could not patent its test, because it "claims natural phenomena."

The district court agreed, ruling that the lab's method was not patentable because it is a patient's metabolite levels that warn a doctor of the drugs' efficacy, not the Prometheus method.

But Prometheus argued that such interpretations of therapeutic and diagnostic methods would likely have a chilling effect on future medical discovery. It claimed that "adoption of the district court's reasoning would have the effect of eliminating all medical treatment and diagnostic patents, when future medical advances will depend on optimizing treatment based on genetic or other testing," the ruling states.

The Washington, D.C.-based appellate panel sided with Prometheus.

Writing for the circuit, Judge Alan D. Lourie said that the key issue for patentability in this case "is whether a claim is drawn to a fundamental principle or an application of a fundamental principle."

Lourie agreed with Prometheus that the method causes "physical transformations" to the human body, and as such it "cannot be unpatentable ... simply because they proceed according to natural laws or occur within the human body."

Lourie cited the testimony of Prometheus's expert, Dr. Yves Théoret, who said, "At the end of the process, the human blood sample is no longer human blood; human tissue is no longer human tissue."

Lourie wrote that the methods of treatment claimed in the patents "squarely fall within the realm of patentable subject matter because they 'transform an article into a different state or thing,' and this transformation is 'central to the purpose of the claimed process,'" (citing a 2008 precedential ruling, In re Bilski).

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