The U.S. Court of Appeals for the Federal Circuit on Monday upheld a Patent Trial and Appeal Board decision awarding CRISPR-Cas9 patents on human and animal gene editing to the Broad Institute of MIT and Harvard.

The ruling settles an initial clash over foundational patents to technology that can be used to add or delete DNA from cells in order to fight diseases, reverse genetic mutations or to improve crop resistance to pests and drought.

The appellate court turned away a challenge from the University of California and research partner University of Vienna, which first developed CRISPR-Cas9 in bacterial cells. The university and its Munger, Tolles & Olson lawyers argued to the Federal Circuit that Broad simply applied its breakthrough to human cells using obvious, conventional techniques. UC sought a declaration that the inventions were patentably indistinct, and that UC's came first.

The Federal Circuit disagreed in University of California v. Broad Institute, saying substantial evidence supported the PTAB's finding that the inventions are distinct. The court pointed to expert testimony about the difficulty of translating CRISPR from prokaryotic, or single-celled organisms, to eukaryotic, or multicellular organisms, as well as comments from UC researchers themselves describing the obstacles.

Researcher Jennifer Doudna, one of the named inventors for UC, had said that while their paper was a big success, “we weren't sure if CRISPR/Cas9 would work in eukaryotes.” Success in doing so would be “a profound discovery,” she said.

“In light of the record evidence, which includes expert testimony, contemporaneous statements made by skilled artisans, statements by the UC inventors themselves, and prior art failures, we conclude that the board's factfinding as to a lack of reasonable expectation of success is supported by substantial evidence,” Judge Kimberly Moore held for a unanimous panel. Chief Judge Sharon Prost and Judge Alvin Schall concurred.

It's a huge win for the Quinn Emanuel Urquhart & Sullivan team that was led by partner Raymond Nimrod. Jenner & Block also represented Broad on the appeal.

“The Federal Circuit made the correct decision,” Broad said in a statement posted on its website. “The patents and applications of Broad Institute and UCB are about different subjects and do not interfere with each other.

“It is time for all institutions to move beyond litigation. We should work together to ensure wide, open access to this transformative technology.”

UC didn't sound like it's finished yet. University general counsel Charles Robinson said in a statement that UC is “evaluating further litigation options. We also look forward to proving that Drs. Doudna and [Emmanuelle] Charpentier first invented usage in plant and animal cells—a fact that is already widely recognized by the global scientific community.” He also noted that the same team has patent applications on the use of CRISPR-Cas9 in plant and animal cells under examination by the Patent Office.

The Federal Circuit seemed to pour fuel on this fire at the end of its opinion. Moore noted that the decision is limited to “the scope of two sets of applied-for claims, and whether those claims are patentably distinct. It is not a ruling on the validity of either set of claims.”

Paul Hastings associate Michael Stramiello, who's been watching the litigation closely but is not involved, said that while Monday's ruling is a big deal, a lot of important questions remain open. “I certainly wouldn't rush out to declare there's a winner here,” he said.

Stramiello said he could imagine the parties settling, given the uncertainty and the difficulties facing Broad in European litigation over the patents.

In the meantime, for licensees of the technology, “It may be a situation where people expect to license from multiple parties.”

CRISPR stands for clustered regularly interspaced short palindromic repeats.