PTAB Terminates Interference Proceeding Between University of California and Broad Institute Regarding CRISPR Gene Editing Claims
Written by Hyeongsu Rick Park and Kerry S. Taylor, Ph.D.
The Patent Trial and Appeal Board (PTAB) terminated a patent interference proceeding between the University of California (UC) and the Broad Institute (Broad), a joint venture of Harvard University and Massachusetts Institute of Technology. The PTAB held that the claims of UC’s patent application did not overlap with the claims of Broad’s patents and patent application sufficiently to support an interference proceeding.
The technology at issue relates to a targeted gene editing system, called CRISPR-Cas9, which uses a combination of protein and RNA to modify the DNA in a cell. The UC inventors developed a CRISPR-Cas9 system that worked to edit the DNA in the cell of a bacteria. UC filed a patent application with claims drawn to 1) a method of editing a target DNA sequence with an engineered CRISPR-Cas9 system and 2) engineered CRISPR-Cas9 systems. None of UC’s claims are limited to any particular type of cell.
Broad later filed patent applications with claims drawn to the use of higher, non-bacterial cells (“eukaryotic” cells). Broad’s claims were directed to 1) a method of altering gene expression in a eukaryotic cell by using an engineered CRISPR-Cas9 system and 2) engineered CRISPR-Cas9 systems used in eukaryotic cells.
On January 11, 2016, the PTAB announced an interference proceeding between UC and Broad. Broad filed a motion arguing that the interference should not have been declared because there is no “interference-in-fact” between the parties’ claims. Broad argued that there was no interference-in-fact because UC’s claims would not anticipate or render obvious Broad’s claims if UC’s claims were considered to be prior art since one of ordinary in the art would not have reasonably expected UC’s CRISPR-Cas9 system to be successful in a eukaryotic cell. Broad cited a number of statements attributed to the UC inventors and UC’s witness stating that it was not known whether the CRISPR-Cas9 system for bacteria would function in eukaryotic cells, and those of skill in the art had doubts about using CRISPR-Cas9 in eukaryotic cells. Broad cited the testimony of its witness to argue that those of ordinary skill in the art would have known that the differences between UC’s bacterial system and a eukaryotic system were significant, and use of UC’s CRISPR-Cas9 system in a eukaryotic system would be unpredictable. Broad also cited failed attempts at transferring other prokaryotic, RNA-based systems into eukaryotic environments as evidence that there was no reasonable expectation of successfully obtaining Broad’s claimed eukaryotic system from UC’s CRISPR-Cas9 system.
UC countered that the statements of the UC inventors relied upon by Broad supported an expectation that the CRISPR-Cas9 system could be successfully used in eukaryotic cells. UC also cited a number of statements attributed to the UC inventors and commentaries regarding UC’s technology as evidence of a reasonable expectation of success. UC further argued that many independent research groups were able to use the CRISPR-Cas9 system in eukaryotic cells after UC published its initial CRISPR-Cas9 results, which allegedly served as further evidence of a reasonable expectation of success. UC also argued that potential problems in achieving the activity of a prokaryotic system in eukaryotic cells raised by Broad could be resolved by routine, well-known solutions.
The PTAB held that there was no reasonable expectation of success that UC’s CRISPR-Cas9 system would work in a eukaryotic cell. The Board viewed the statements provided by the UC inventors as expressing eagerness to learn whether the CRISPR-Cas9 system would work in eukaryotic cells, not evidence demonstrating that it would be routine to do so. The PTAB also concluded that the number of research groups who attempted to use the CRISPR-Cas9 system in eukaryotic cells may be evidence of a motivation, but not evidence of a reasonable expectation of success. The PTAB found that the totality of the evidence cited by both parties does not support a reasonable expectation of success for using UC’s CRISPR-Cas9 in eukaryotic cells, and Broad’s evidence of difficulty transferring certain prokaryotic systems into eukaryotic systems indicates that those in the art would not have had a reasonable expectation of success using UC’s CRISPR-Cas9 in eukaryotic cells.
Based on the evidence, the PTAB held that Broad had demonstrated that its claims, all of which are limited to CRISPR-Cas9 systems in a eukaryotic environment, are not drawn to the same invention as UC’s claims. Thus, the PTAB concluded that the parties’ claims do not interfere with each other and terminated the interference.
This case illustrates hurdles a party in an interference may encounter when the inventors make statements about the scope of their invention and the level of difficulty in their field of endeavor. It also demonstrates that inventors in less predictable fields can experience difficulty establishing that their experimental results are sufficient to accord to them inventive credit for similar results in other systems.