CRISPR-Cas9 editing, the technology which gives scientists the ability to selectively edit genes with relative ease, makes the headlines on a regular basis. Here, we give a brief update on the status of the interference proceedings in the United States and a recent study aimed at improving the safety of the technology in human embryos.

Interference – Appeal Pending

In February 2017, the US Patent Trial and Appeal Board (PTAB) made its much-awaited decision in the CRISPR-Cas9 interference proceedings. The PTAB found no interference-in-fact between patents and a patent application of the Broad Institute, MIT and Harvard, and a patent application filed earlier by UC Berkeley, the University of Vienna and Emmanuelle Charpentier.

UC Berkeley, the University of Vienna and Emmanuelle Charpentier have since appealed the decision, which found that their earlier patent application, which covered the use of CRISPR-Cas9 in all environments, did not render obvious the Broad’s claims to using CRISPR-Cas9 in eukaryotic cells. The US Court of Appeals for the Federal Circuit in Washington, D.C. will make its decision in due course, but if it does decide that the parties’ patents and patent applications interfere, the PTAB would then have to decide who is entitled to patents for the use of CRISPR-Cas9 in animals, plants, bacteria and other environments.

For the time being, licensees wishing to carry out gene editing in eukaryotic cells are still faced with two sets of potential licensors – indeed, both sets of licensors have concluded and continue to enter into licensing deals.

Improving the safety of CRISPR-Cas9 in humans?

In August 2017, a paper was published in Nature by a team at Oregon Health and Science University which has contributed to the ongoing discussion on the safety of using CRISPR-Cas9 in humans. The team used CRISPR-Cas9 to try to correct a mutation in the MYBPC3 gene in human embryos – mutations in this gene cause thickening of the heart muscle, which is the most common cause of sudden death in young athletes. The team reported that the technique it used minimised unwanted (‘off-target’) mutations and reduced the generation of mosaics (where embryos contain a mix of cells with different genetic sequences), both of which are major hurdles to overcome before the technique can be used safely in humans. However, there is still a lot of research to be done before CRISPR editing in humans is proved to be safe, and an important step will be for other teams to validate the results of this study.