In the wake of the decision of the U.S. Supreme Court in Mayo Collaborative Services v. Prometheus Labs (see IP Update, Vol. 14, No. 6) the U.S. Court of Appeals for the Federal Circuit once again wrestled with the issue of when a patent claim is directed to a non-patent eligible "abstract idea."

Speaking through Justice Breyer, a unanimous Supreme Court of the United States (reversing the U.S. Court of Appeals for the Federal Circuit) held that claims directed to a blood-testing method are invalid because they do not define patent-eligible subject matter.