NEW YORK (360Dx) – A diagnostic test used by Mayo Clinic to detect a rare neurological disease involves standard techniques and is not subject to patent law, a federal appeals court ruled Wednesday.
The appellate court's decision to uphold a district court ruling in the patent dispute effectively denied claims by Quest Diagnostics' Athena Diagnostics division that it was owed royalties for the testing. The US Court of Appeals for the Federal Circuit sided with Mayo in a 2-1 decision.
The case centers around testing used to detect a neurological disorder called myasthenia gravis. Athena Diagnostics is the exclusive licensee of a patent for detecting antibodies to a protein called muscle-specific tyrosine kinase (MuSK). For approximately 20 percent of Myasthenia gravis sufferers, the disease is not detectable through more common methods and can only be identified through the detection of MuSK antibodies, according to court documents.
Athena markets a test called FMUSK based on the patent, and the company contends that two competing tests developed by Mayo Collaborative Services infringe on Athena's MuSK patent, US Patent No. 7,267,820. Mayo successfully argued in district court that the tests involve "natural law" and are "ineligible" for patent protection, according to court documents.
Writing for the majority, Circuit Judge Alan Lourie noted that while the identification of the antibodies involves "natural law" and is not subject to patent, the question before the court was whether the testing method used was sufficiently innovative to merit patent protection.
"We agree with Mayo that the steps of the claim ... whether viewed individually or as an ordered combination, only require standard techniques to be applied in a standard way," he wrote.
In a dissenting opinion, Circuit Judge Pauline Newman noted that the line separating patent-eligible and patent-ineligible diagnostics is unclear. She expressed concerns that the court's opinion has potential to stifle innovation.
"This court's decisions on the patent-ineligibility of diagnostic methods are not consistent, and my colleagues today enlarge the inconsistencies and exacerbate the judge-made disincentives to development of new diagnostic methods, with no public benefit," she wrote.
Mayo's argument was based in part on a 2012 Supreme Court case, Mayo Collaborative Services v. Prometheus Laboratories, which determined that measuring metabolite levels of drugs in patient blood involves laws of nature and cannot be patented. But while concerns have been raised that the ruling in that case and others like it would negatively affect the diagnostic industry, one study suggests that hasn't been the case.
A study of 31,000 patent applications between 2002 and 2015 by Duke University's Arti Rai and Santa Clara University's Colleen Chien found that the number of core diagnostic patent applications was higher in years following the ruling.
Quest declined to comment on the case. In an email, Mayo Clinic and Mayo Clinic Laboratories expressed pleasure with the ruling, but declined to comment on the specifics of the case.