“On second review, the PTAB was again ‘not persuaded that CVC has met its burden as junior party of showing that its inventors conceived of an embodiment of Count 1 before the Broad inventors had reduced the invention to practice.’”
On remand from the U.S. Court of Appeals for the Federal Circuit (CAFC), the Patent Trial and Appeal Board (PTAB) on Thursday reaffirmed its decision that The Broad Institute, Inc., Massachusetts Institute of Technology, and President and Fellows of Harvard College (“Broad”) were the first inventors of the use of CRISPR-Cas9 gene editing in eukaryotic cells.
Jennifer Doudna of the University of California, Berkeley and Emmanuelle Charpentier, a microbiologist from Umeå University in Sweden and the Max Planck Institute for Infection Biology in Berlin, were awarded the Nobel Prize in Chemistry in 2020 for their work on the CRISPR (“clusters regularly interspaced palindromic repeats”) gene editing technology, which has been the subject of a heated patent debate over alleged simultaneous inventorship with Broad for years.
In May 2025, the CAFC issued a precedential opinion vacating and remanding the PTAB’s determination awarding priority to Broad, finding the PTAB applied the wrong standard by requiring the Regents of the University of California, the University of Vienna and Charpentier (“CVA”) to show their invention was known to work. The CAFC explained that conception doesn’t require certainty of success and remanded for reevaluation under the correct framework.
While the court reversed the PTAB on conception, it upheld the finding that CVC’s 2012 provisional applications lacked adequate written description. The applications did not adequately show possession of an operable CRISPR-Cas9 system in eukaryotic cells, even though they described the core components of the technology, said the court. As a result, CVC could not rely on those early filings to establish a constructive reduction to practice.
On second review, the PTAB was again “not persuaded that CVC has met its burden as junior party of showing that its inventors conceived of an embodiment of Count 1 before the Broad inventors had reduced the invention to practice.”
The PTAB first addressed the CAFC’s ruling that its original decision conflated “‘the distinct legal standards for conception and reduction to practice’ by not considering routine methods and skill, focusing instead on the CVC scientists’ statements of uncertainty about whether their experiments had succeeded and suggestions for modifications to the system they were using.”
While CVC posed three arguments to prove conception on remand, the Board said that nothing in the CAFC decision required them to consider only certain evidence this time around, rather than a “preponderance of the totality of evidence,” as in their original decision.
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The Board ultimately found that the level of ordinarily skilled artisan, the testimony of CVC’s witnesses, the CAFC’s decision on written description, and other evidence demonstrated that “one of ordinary skill at the time could not have reduced an operative eukaryotic CRISPR-Cas9 system to practice based on the information reflected in CVC’s alleged conception without extensive research or experimentation.”
The Board said the evidence showed that the inventors were still identifying important aspects of the invention “even after the Broad inventors had reduced the invention to practice.” The PTAB also rejected CVC’s argument that one of Broad’s inventors derived the invention, citing an email as evidence. But “to prove derivation, CVC must first establish that its inventors conceived of the claimed subject matter before the Broad inventors,” said the Board, which it had failed to do.
