Brief of Amici Curiae Interested Patent Law Professors in Support of Neither Party in Prometheus v. Mayo

In Prometheus v. Mayo, the district court erred in characterizing an entirely man-made biological correlation, which did not and could not exist absent human intervention, as an unpatentable “natural phenomenon" under 35 U.S.C. § 101. Contrary to the district court’s conclusion, the mere fact that the breakdown of a man-made, non-naturally occurring drug (i.e., drug metabolism) involves natural processes in the body does not render the breakdown of the drug a natural process, nor does it render a correlation between these non-naturally occurring drug breakdown products (i.e., drug metabolites) and the optimal dosage of the drug a natural phenomenon. If not reversed, the decision below could cast doubt on the patentability of many important innovations, particularly in the area of diagnostics and personalized medicine. In re Bilski did not obviate the necessity to accurately distinguish between non-natural and natural phenomena, and the instant case provides appropriate facts for this Court to provide critical guidance for future courts faced with this important inquiry.