On March 20, 2012 the U.S. Supreme Court clarified the scope of patentable subject matter, holding that Prometheus’ patent claims directed to processes that help doctors determine whether certain dosage levels of thiopurine drugs used to treat gastrointestinale disorders like are too high or too low were invalid for lack of subject matter. The representative claim considered by the Supreme Court read:
A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:
(a) administering a drug providing 6-thioguanine to a subject having said immune-mediated gastrointestinal disorder; and
(b) determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder,
wherein the level of 6-thioguanine less than about 230 pmol per 8×10^8 red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and
wherein the level of 6-thioguanine greater than about 400 pmol per 8×10^8 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.
The Court held that the subject matter of the representative claim set forth a law of nature, namely the relationship beween the concentration of certain metabolites in the blood and the likelihood that a dosage of a thiopurine drug would be ineffective or cause harm. The additional recited steps of of “administering”, “determining” only set forth routine, conventional post-solution activities already practiced by the scientific community that add nothing of significance to the natural laws themselves. Appending conventional steps, specified at a high level of generality, cannot convert laws of nature, natural phenomena or abstract ideas into patentable subject matter. Because the claims effectively claim the underlying laws of nature themselves, the Court concluded the claims were invalid.
The opinion reversed an en banc opinion of the Court of Appeals for the Federal Circuit that had previously found the claims to be patent-eligible using the “machine-or-transformation” test recently applied by the Supreme Court in Bilski. Here, however, the court held that while the machine-or-transformation test “is an ‘important and useful clue‘ to patentability”, the machine-or-transformation test does not trump the exclusion of laws of nature from patentable subject matter.
The U.S.S.C. slip opinion may be found here.