Pondering Patents and Laws of Nature

“You take wood, you put it on a grate, you light it, and you get heat…[s]o I can get a patent for that?”

Chief Justice John G. Roberts Jr. asked this of Donald B. Verrilli Jr., the solicitor general, last week during oral arguments in the matter of Mayo Collaborative Services v. Prometheus Laboratories, No. 10-1150, in a case that would determine whether observed correlations between drug dosages and medical treatment were eligible for subject matter protection under patent law.  The patent in question concerns the relationship between thiopurines, which are drugs used to treat immune-mediated gastrointestinal disorders, and metabolites in patients’ blood.

One of the claims in the patent recites a method of optimizing treatment, whereby thiopurines are administered to the patient and the level of a specific metabolite is determined in the blood.  A high metabolite level indicates a need to reduce the dosage and a low metabolite level indicates a need to increase the dosage.  Another claim in the patent recites the same method, except to exclude the administering of the thiopurines.  Administering the drug was known in the prior art; detection of the metabolites was known in the prior art.

According to Prometheus Laboratories, however, the correlation between metabolite levels and effectiveness or toxicity of the drug was not known in the prior art and sued Mayo for patent infringement.  Under current patent law, a law of nature is not patent eligible but an application of a law of nature is patent eligible.  Mayo countered that what Prometheus sought to protect was an “abstract” idea based on natural phenomena and preempted a “whole field” from use.  The government sided with neither party, arguing that while the method was patentable, it could then probably be challenged as invalid because it was obvious and insufficiently novel.

In 2010, in Bilski v. Kappos, the Court heard a case involving the patent eligibility of a method for hedging risk in commodities trading.  The Court ruled that the claimed method was not eligible subject matter because it was abstract, but the court shed little light on the definition of “abstract” – setting the stage for the Mayo case last week.

There is a risk that the Court’s eventual ruling in the spring will create additional headaches for the patent system.  Using the eligibility requirement to address patent claims as anything beyond a coarse filter for patents ignores the other patentability doctrines that can be used to determine whether an invention is acutually new.  Eligibility rules often require judges to ponder the imponderable, or at the very least nonsensical, by asking courts to be in charge of determining what “nature” is in order to decide the question of patent eligibility.  Not only that, but eligibility rules then become mired in semantical debates over the precise form in which claims are drafted.

As for Chief Justice Robert’s query at the beginning, the answer is…maybe.