The cloud of uncertainty over patent eligibility of patents for medical diagnostic methods remains. On Monday, the Supreme Court declined the opportunity to revisit patent eligibility under its two-step Mayo test when it denied certiorari in Athena Diagnostics v. Mayo Collaborative Services — a case in which the en banc Federal Circuit panel split 7 to 5 on whether medical diagnostic inventions, such as the one at issue in Athena, are patent eligible under Mayo.

The inventors of Athena’s patent discovered that 20 percent of patients who have myasthenia gravis (MG), a rare neurological disorder that causes patients to experience muscle weakness and symptoms including drooping eyelids, double vision and slurred speech, did not produce acetylcholine receptor autoantibodies, but instead produced autoantibodies to a membrane protein called MuSK. Based on this discovery, the inventors developed and patented methods of diagnosing neurological disorders such as MG by, inter alia, detecting autoantibodies that bind to MuSK.

Indeed, while all 12 active judges of the Federal Circuit agreed that diagnostic methods in Athena should be patent eligible under Section 101, the majority indicated that their hands were tied in light of the Supreme Court’s precedent. As a result, there was an unprecedented cry from the Federal Circuit for the Court to clarify whether diagnostic methods should be patent eligible. Further highlighting the need for the Court’s guidance are the numerous amici briefs that were filed in support of the petition. The U.S. government also urged the Supreme Court to take up Athena. These cries for the Court’s help remain unheeded.

The denial of certiorari in Athena and two other cases concerning 101 issues on the same day may be a signal that the Supreme Court is waiting for Congress to resolve what is patent eligible subject matter. Regardless, the lack of clarification from the Supreme Court will likely chill innovation of new diagnostic methods needed by the afflicted public.