A decision has been reached by the United States Patent Trial and Appeal Board (PTAB) in relation to the ownership dispute between the Broad Institute and the University of California on CRISPR-Cas9 technology for genome editing. The PTAB ruled Broad’s claims are not anticipated by UC’s patent application.

The United States Patent Trial and Appeal Board (PTAB) have released its decision[1] in relation to the interference dispute over CRISPR-Cas9 technology between the Broad Institute and University of California (UC).

UC, were first to file their application relating to CRISPR-Cas9 methodology for studies in cell-free systems.[2] However, Broad have granted patents and applications[3] covering CRISPR-Cas9 methods for genome editing in eukaryotic cells (including human).

UC claim they were the first to invent the CRISPR-Cas9 methodology under the US’s first to invent patent law and that they (UC) were entitled to ownership of the invention. Importantly, the method of UC’s application does not involve genome editing in eukaryotic cells and none of the claims between the patents and applications were identical.

The PTAB needed to decide whether UC’s patent claims were prior art to Broad’s patents, and if prior art, would they render the claims of Broad’s patents obvious.

It was acknowledged that UC's claims would not anticipate Broad's claims - because all of Broad's claims were limited to use of CRISPR in eukaryotic cells. The UC's claims did not have any limitation relating to the context in which CRISPR was to be used. So to win, Broad needed to show that their claims were non-obvious in light of UC’s method.

The PTAB gave considerable weight to statements and disclosures made by UC inventors (Jinek and Doudna) questioning whether the CRISPR-Cas9 system would work in eukaryotes. Interestingly, UC's own witness was also sceptical whether the skilled worker would have had an expectation that the invention could be used successfully in eukaryotic cells saying: “There is no guarantee that Cas9 will work effectively on a chromatin target or that the required DNA-RNA hybrid can be stabilized in that context.”

Consequently, the PTAB considered that if the inventors questioned that CRISPR would work in eukaryotes, then the normally skilled addressee would be even more uncertain, and that “no guarantee” did not indicate an expectation of success. Therefore, Broad’s claims were not obvious and their patents were allowed.