The U.S. Court of Appeals for the Federal Circuit has recently decided three important cases pertaining to patent-eligible subject matter for personalized medicine diagnostic tools, therapeutic treatments, and DNA sequences. Although still under further requests for appellate review, the decisions in Prometheus Laboratories v. Mayo Collaborative Services (“Prometheus”), Associates for Molecular Pathology v. U.S. Patent and Trademark Office, et al. (“Myriad”) and Classen Immunotherapies v. Biogen Idec (“Classen”) are largely consistent and provide much needed clarity in this area of patent law. These cases follow the U.S. Supreme Court’s 2010 decision on statutory patentable subject matter of method claims in Bilski v. Kappos (“Bilski”), which validated the use of the machine-or-transformation test as an important guide to patent eligibility in the life sciences.

In essence, it is clear from these cases that diagnostic method claims are patent-eligible to the extent they recite physically transformative steps and do not merely require mental comparisons or thought analyses. Furthermore, “isolated” DNA is also patent-eligible because it is a unique chemical entity that does not exist in nature.