The U.S. Court of Appeals for the Federal Circuit has released its decision in Prometheus Laboratories, Inc. v. Mayo Collaborative Services (Fed. Cir. 2009) (PDF), finding patent-eligible subject matter in claims for a method of medical treatment by "administering" a drug and then "determining" the level of metabolite levels in the subject, where certain levels of metabolites indicated a need to change the dosage of the drug.
The CAFC applied the machine-or-transformation test articulated in its earlier decision in In Re Bilski and found that the step of "administering" the drug effected a transformation of the human body, and the step of "determining" involved manipulation of a bodily sample. The claims in Prometheus> were distinguished from mere data-gathering and correlation steps also used in diagnostic methods.
The Supreme Court of the United States granted certiorari in Bilski in June 2009.