The Federal Circuit on Friday saved Regenxbio and the University of Pennsylvania's gene therapy patent, finding that splicing together genes from different organisms results in a molecule that is "markedly different from anything occurring in nature," rendering the therapy patent eligible.

In the precedential decision, the appeals court panel dinged a Delaware federal court for deeming ineligible the patent that the university and licensee Regenxbio had asserted in a suit against Sarepta Therapeutics Inc.

At the center of the eligibility question is the patented technology's use of a human-made host cell containing a recombinant nucleic acid molecule, which is a combination of two pieces of genetic material from two different organisms.

The Delaware federal court had found that the patent doesn't do much besides combine two pieces of naturally occurring materials without any modifications. But the Federal Circuit disagreed, saying the patent covers a human-induced combination of genetic materials that behaves materially differently from naturally occurring phenomena.

"It is uncontested that the claimed host cells include a recombinant nucleic acid molecule that does not and cannot exist in nature," the opinion said, adding that, "the recombinant nucleic acid molecule must be spliced together via human intervention from at least two different species to meet the claim limitations."

To come to its conclusion, the appeals court panel took a tour through several precedential decisions addressing patent eligibility for inventions involving bacteria and DNA. One such case is the U.S. Supreme Court's 1948 decision in Funk Brothers Seed Co. v. Kalo Inoculant Co., in which the justices deemed ineligible a root nodule bacteria that could be used in growing legumes, saying it was "only some of the handiwork of nature."

Also relevant to the case is the Supreme Court's 1980 decision in Diamond v. Chakrabarty, which dealt with genetically engineered bacterium for use in breaking down crude oil, a technology that the court deemed patent eligible.

Friday's opinion also cited the court's 2013 opinion in Molecular Pathology v. Myriad Genetics, Inc., which was a mixed decision that found some patent claims ineligible since they merely isolated genes relevant to breast cancer occurrence, while finding other claims eligible because they covered the creation of a complementary deoxyribonucleic acid sequence out of messenger ribonucleic acid.

Lastly, in ChromaDex, Inc. v. Elysium Health, Inc., the Federal Circuit found claims covering the isolation of a vitamin in milk to be patent-ineligible, since the claims aren't significantly different from milk.

The appeals court said Friday that the Regenxbio patent is more analogous to the claims in the Chakrabarty case. Just like the genetically engineered bacterium in that case, the gene therapy technology at issue is "not nature's handiwork," the opinion said.

And like the claims that survived the mixed decision in the Myriad case, the patent covers "something new" — the recombinant nucleic acid molecule — according to the Federal Circuit.

The gene therapy is thus different from the legume bacteria claims in the Funk Brothers case, which the Federal Circuit described as little more than "an improvement in packaging" of natural materials.

"Genetically engineering two nucleic acid sequences from separate species into a single molecule and then transforming a host cell in order to incorporate that new molecule into it … is materially different from growing more than one naturally occurring bacteria strain in a culture where none of the bacteria undergo any change from their natural state," the opinion said.

Gene therapy treatments, like the one at issue in the opinion, can be used to treat genetic disorders like cystic fibrosis and sickle cell disease.

Representatives for the parties did not respond to requests for comment.

U.S. Circuit Judges Timothy B. Dyk, Todd M. Hughes and Kara F. Stoll sat on the panel for the Federal Circuit.

The patent-at-issue is U.S. Patent No. 10,526,617.

Regenxbio and The Trustees of the University of Pennsylvania are represented by Susan E. Morrison and Deanna Jean Reichel. The trustees were also represented by Julie S. Goldemberg and Amy M. Dudash of Morgan, Lewis & Bockius LLP.

Sarepta is represented by Robert B. Wilson, James Baker and Anastasia M. Fernands of Quinn Emanuel Urquhart & Sullivan LLP.

The case is Regenxbio Inc. et al. v. Sarepta Therapeutics Inc., case number 24-1408, in the U.S. Court of Appeals for the Federal Circuit.