The Effects of Myriad and Mayo on Molecular Test Development in the US and Europe: Interviews from the Frontline

US Supreme Court decisions in Mayo Collaborative Services v. Prometheus Laboratories and Association for Molecular Pathology v. Myriad Genetics Inc. caused US and European law on what is patentable subject matter to diverge significantly. Both cases related to molecular tests and changed decades of patent practice. Whether the decisions adversely affect the development of molecular tests in the United States and Europe has been a matter of much speculation but limited empirical investigation. This interview-based study has three main findings. First, Myriad and Mayo have negatively affected the development of some molecular tests. Notably, half of the US university technology-transfer offices interviewed decided not to develop tests, and many other organizations have found the legal uncertainty following the cases problematic. Second, small "patent-precarious" organizations—those that rely heavily on patents for competitive advantages, such as technology-transfer offices—have been the most affected because patent protection is now often weaker and more difficult