Patenting Medical Diagnostic Procedures


This article is a follow on to my July 19, 2019 post entitled Patenting Medical Devices and Procedures.  It may be useful to review this earlier blog post.  What prompts this new post is the pending petition of Athena Diagnostics Inc. regarding the invalidation of its patent for detecting a neurological disorder (Myasthenia gravis).  I discussed this case, Athena v. Mayo, in the earlier blog.  Athena is petitioning the Supreme Court after the Federal Circuit reluctantly invalidated the patent based upon Supreme Court precedent.

This new blog is also inspired by today’s blog of Professor Dennis Crouch, author of the long established and respected “Patently O” blog.  His article is entitled “Athena v. Mayo: Whither Diagnostic Method Patents”.


The courts have been concerned with issuance of patents that incorporate “natural law or phenomena”.  Their concern is that a single patent could monopolize broad application and utilization of natural phenomena.  There is a competing line of cases wherein a specific application using natural law or phenomena to control a machine ro transform a physical state of matter is patentable subject matter.  I frequently cite the 1981 case of Diamond v. Diehr wherein utilization of the Arrhenius equation as a part of an industrial operation of controlling the vulcanization of rubber was deemed patentable subject matter. 

The 2012 case of Mayo v. Prometheus signaled the current controversy.  The Supreme Court reasserted that “Laws of nature, natural phenomena and abstract ideas are not patentable”.  The Court invalidated a patent based upon its determination that the claims defining the invention did not add enough correlations of natural law and diagnostic steps to qualify as a patent-eligible process that applied natural law.  

Significant to my analysis is the subsequent and well known case of AMP v. Myriad Genetics.  This case is well known for the holding that a person’s DNA is not patentable subject matter.  However perhaps overlooked is the DNA modified by the testing process was deemed to be possible patent-eligible matter.  Note an isolated natural occurring DNA segment was not patentable. 

Athena v. Mayo, the case now subject of this article, previously resulted in the invalidation by the Federal Circuit of Athena’s patent for detecting previously undetectable propensity for a neurological disorder.  The testing method pertained to detection of certain antibodies to a protein cell muscle specific to tyrosine kinase MuSK.  What is significant is that the test procedure created a modified cell (labelled cell) and monitoring the modified cell “wherein the presence of the said label is indicative of said mammal is suffering from said neurotransmission or developmental disorder related to muscle specific tyrosine kinase (MuSK)”. 

Federal Circuit, in invalidating the Athena patent, reluctantly relied upon the Supreme Court decision of Mayo v. Prometheus.  The Court determined that the Athena patent relied only upon the natural relationship between the presence of the MuSK complex and neurotransmission of developmental disorder.  The medical techniques to determine the existence of the naturally occurring MuSK complex were not novel or innovative. 

Now, Athena is back petitioning the Supreme Court to consider that the medical diagnostic method requires creation of an artificially created cell, i.e. not a naturally occurring cell.  Recall from above that the Supreme Court determined that genetically altered DNA was patentable subject matter in AMP v. Myriad Genetics.  


The inventor is challenging the misapplied broad brush wielded by the Supreme Court to carve out patentable subject matter.  First, the procedure is applied to a new group of cells.  That is the basic technique is known but never applied to cells of this type.  Second, the testing creates a new and non-naturally occurring cell.  For instance, the cell can be marked with a radioactive label.  Therefore the test is not merely monitoring a relationship between naturally occurring cells and a physical condition or malady.  This, in my opinion, should be patentable subject matter.