Background
Athena Diagnostics held patent rights to a method for diagnosing a form of myasthenia gravis — a debilitating neuromuscular disease — by detecting autoantibodies that the patient’s immune system produces against muscle specific tyrosine kinase (MuSK), a naturally occurring protein. The diagnostic method involved exposing a patient’s bodily fluid to a labeled form of MuSK and detecting whether the patient’s antibodies bound to it, indicating disease. The key scientific insight was the correlation between the presence of MuSK autoantibodies and the disease — a natural relationship that was newly discovered by the inventors.
Mayo Collaborative Services, a clinical laboratory, offered a competing test. Athena sued for patent infringement. The District of Massachusetts held the claims ineligible under § 101, relying on the Supreme Court’s 2012 decision in Mayo v. Prometheus, which had broadly invalidated diagnostic patent claims based on natural correlations.
The Court’s Holding
The Federal Circuit panel affirmed. Applying the Mayo/Alice framework, the court held the claims were directed to a natural phenomenon — the correlation between MuSK autoantibodies and myasthenia gravis — and that the specific laboratory techniques used to detect the antibodies were conventional, providing no inventive concept. The panel acknowledged the unfortunate result but said it was bound by the Supreme Court’s Mayo precedent.
The en banc denial in July 2019 was remarkable for generating eight separate opinions — four concurring and four dissenting — from a court of twelve active judges. Multiple judges wrote expressly that they agreed the result was wrong but felt bound by Mayo. Others argued the court had room to distinguish Mayo and chose not to. The case drew intense attention from the life sciences industry and Congress, and Athena petitioned the Supreme Court for certiorari, which was denied in 2020.
Key Takeaways
- After Mayo, the Federal Circuit has consistently invalidated diagnostic method patents that are based on newly discovered natural correlations, even if the correlation was unknown before the inventor discovered it.
- The use of conventional laboratory techniques to detect a natural phenomenon does not save a diagnostic patent at Alice/Mayo step two.
- The eight separate en banc opinions exposed a deeply fractured Federal Circuit that views the current § 101 doctrine as problematic but feels bound by Supreme Court precedent.
- Athena is widely cited as a leading example of the chilling effect of Mayo on investment in diagnostic innovation — if you cannot patent a new diagnostic method, there is less incentive to discover and develop it.
Why It Matters
Athena Diagnostics is one of the most discussed § 101 decisions of the post-Mayo era because it vividly illustrated the human cost of the diagnostic patent eligibility problem. Myasthenia gravis is a serious disease, the MuSK correlation was a genuine scientific discovery, and the inventors invested real resources to develop and validate the diagnostic test. Yet under current law, that discovery is unpatentable because it is a natural phenomenon — even though no one knew about it before the inventors found it.
The eight concurrent and dissenting opinions on en banc denial — an unusual and deliberately public display of judicial frustration — sent a clear signal to Congress and the Supreme Court that the courts cannot resolve the diagnostic patent problem on their own. The case became a centerpiece of the bipartisan Senate hearings in 2019 on § 101 reform and is still cited in ongoing legislative discussions about how to restore patent protection for medical diagnostics.