A method to assess the risk of fetal Down’s syndrome is not patent-eligible subject matter, the U.S. Court of Appeals for the Federal Circuit has ruled, relying on recent high-profile cases about medical diagnostic patents.

On November 20, a unanimous panel reversed a lower court ruling that Intema Ltd.’s screening patent was patent-eligible subject matter. The Federal Circuit did not reach the district court’s holding that Intema’s claims were anticipated and obvious, but it affirmed the court’s summary judgment for PerkinElmer Inc.

Judge Kathleen O’Malley wrote the opinion in PerkinElmer Inc. v. Intema Ltd., joined by judges William Bryson and Evan Wallach.

O’Malley wrote that two rulings “dictate the result we reach today.” One is the U.S. Supreme Court’s unanimous March ruling in Mayo Collaborative Services v. Prometheus Laboratories Inc., which held that two patents on a diagnostic test used to treat autoimmune diseases invalid.

Justice Stephen Breyer wrote the majority opinion in Mayo, holding that patents based on the use of a natural law must also contain an “inventive concept.” 

The other is the Federal Circuit’s split August ruling in Association for Molecular Pathology v. Myriad Genetics Inc. 

The Myriad case held that isolated human genes are patent-eligible but that Myriad’s method claims for “comparing” or “analyzing” DNA sequences are not.

Those two cases dealt with similar process claims, O’Malley wrote. She noted that the patent does not require any action besides comparing data gathered in the first and second trimesters of pregnancy with known statistical information.

She also observed that Intema also claims a law of nature, which is “the relationship between screening marker levels and the risk of fetal Down’s syndrome.”

“Looking to the claims as a whole, the steps in combination do not make the ineligible mental step and natural law patent-eligible,” O’Malley wrote.

O’Malley also explained that the technology in Myriad is different because the host cells in that test were man-made and therefore, patent- eligible subject matter.

Jim Badke, a New York partner at Boston’s Ropes & Gray who argued for PerkinElmer, said, “I’m happy that the Federal Circuit, in our case, went the way it did because we see that as being consistent with Mayo.”

The PerkinElmer ruling also gives some insight on how at least some of the court feels about patent eligibility in light of its October order to hold an en banc rehearing of CLS Bank International v. CLS Services Ltd., Badke said. The July 2-1 ruling in CLS reversed a lower court’s summary judgment that several claims in patents involving computerized trading platforms for exchanging obligations were ineligible for a patent. CLS wasn’t cited in the PerkinElmer ruling.

Intema hasn’t decided what to do, said Lawrence Rosenthal, an of counsel to New York-based Stroock & Stroock & Lavan who co-chairs the firm’s intellectual property practice group and who argued for the London-based Intema.

“I’m surprised and I strongly disagree with the result. Under the court’s reading, it’s doubtful that any diagnostic test is patentable,” Rosenthal said.

Sheri Qualters can be contacted at squalters@alm.com.