On 15th February, the US Patent and Trademark Office (USPTO) determined that patents granted to the Broad Institute concerning CRISPR editing in eukaryotes did not interfere with those filed by the University of California, Berkeley. This ruling could mark the end of a long and contentious battle over the intellectual property rights to this breakthrough technology.

The CRISPR-Cas9 method is based on a natural system used by bacteria to fend off viruses, and its potential as a gene editing tool in cell-free systems was first demonstrated in 2012 by Jennifer Doudna of Berkeley, and Emmanuelle Charpentier, then of Umeå University in Sweden. Subsequently, several groups, including one led by Feng Zhang of the Broad Institute of MIT and Harvard in Cambridge, Massachusetts, showed that CRISPR–Cas9 also worked in living eukaryotic cells – an important advancement towards the development of human therapeutics.

Although Berkeley’s team was first to file for a patent, the Broad opted for an expedited review process, and its patents were issued first. Arguing that it had invented the technique, lawyers representing Berkeley filed for an ‘interference’ proceeding as an attempt to have the Broad’s patents thrown out. Thus began a year-long battle to establish who ‘owned’ the invention.

The Broad’s key argument was that Berkeley’s initial patent filing described using CRISPR–Cas9 in cell-free systems, but did not specify how it could be adapted for use in eukaryotes, including humans. Berkeley counterargued that the application of CRISPR–Cas9 to eukaryotic cells was obvious and that the leap could have been made by any person “of ordinary skill”, such as a postdoc with relevant expertise.

According to USPTO, “Broad provided sufficient evidence to show that its claims, which are all limited to CRISPR-Cas9 systems in a eukaryotic environment, are not drawn to the same invention as UC’s claims, which are all directed to CRISPR-Cas9 systems not restricted to any environment.” Further, the invention of the system in eukaryotic cells “would not have been obvious over the invention of CRISPR-Cas9 systems in any environment, including in prokaryotic cells or in vitro”.

In a statement from Berkeley, Jennifer Doudna stated that the interference decision means USPTO would now be able to move forward on her own patent applications. The Broad, meanwhile, has pledged to continue to “make this transformative technology freely available to the worldwide academic community and for commercial and human therapeutic research”.

However, if the Berkeley patents are granted, this will potentially mean that companies and research institutions relying on CRISPR-Cas9 will need to license technology from both parties. As Doudna put it: “Broad Institute’s patent is for green tennis balls but the patent we will have is for all tennis balls”.