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A Pivotal Technology in the Development of Gene Therapy: The ongoing CRISPR-Cas9 patent battle

Aaraf Dewan, M.Sc. Student Writer, Windsor Law LTEC Lab  J.D., 2019

On February 15,2017, the United States Patent and Trademark Office (USPTO decided to uphold the patents from both Feng Zhang and Jennifer Doudna regarding the CRISPR-Cas9 gene editing technology. The USPTO rejected Doudna’s claim that Zhang’s patents, had interfering claims with her earlier patents on the CRISPR-Cas9 technology. These patents cover biotechnology which could be adopted for gene therapy procedures in hospitals. Gene therapy procedures have the potential for curing many diseases like cancer and Alzheimer’s which we are currently unable to adequately treat using drug therapy. Due to their implications in medicine. patent battles over technology capable of being used in gene therapy are extremely important in the search for cures to such diseases. The CRISPR-Cas9 patent battle has garnered much attention from scientists and lawyers alike as it has the potential for being the first gene editing system adopted for gene therapy in patients. The outcome in this patent battle will likely shape the future of development of gene therapies,

What is CRISPR-Cas9?

The CRISPR-Cas9 gene editing system is a breakthrough gene editing system capable of performing gene editing techniques cheaper, easier, and more efficiently than previous technologies. Due to these aspects of the technology, it has quickly been adopted by researchers seeking to perfect gene therapy procedures for use in hospitals. CRISPR-Cas9 is a gene editing system which originated in bacteria as the protein Cas9, a molecule capable of cleaving segments of DNA[1]. Jennifer Doudna and her lab at the University of California modified this protein through a process known as protein engineering to create the CRISPR-Cas9 system, which can target specific DNA sequences and modify them[2]. Feng Zhang’s lab at the Broad Institute also modified the technology to allow for its use in eukaryotic cells, a feat that researchers were previously unable to accomplish with the technology[3].

The patents of Jennifer Doudna and Feng Zhang

The Doudna lab from the University of California and the Zhang lab at the Broad Institute of MIT and Harvard had both filed for patent rights to the CRISPR-Cas9 technology back in 2012. Doudna had filed her patents first in May 2012 on the general use of the CRISPR-Cas9 system for editing genes and her patents are currently still under review. Zhang had filed his patent afterwards under an expedited review process in December of 2012 and was granted the first patent on the technology in April 2014. Zhang filed patents for the specific use of CRISPR-Cas9 in eukaryotic cells, a classification of cell type which animals and plants are categorized under. What this meant is that while Doudna had rights to the use of CRISPR-Cas9 in virtually all organisms, Zhang would also hold rights to the use of CRISPR-Cas9 in its use in the most lucrative applications, the use in animals, plants, and humans. Doudna filed for an interference proceeding to get Zhang’s patents taken down, claiming that the claims in Zhang’s patents interfered with Doudna’s patents which were filed first. On February 15, 2017, the US Patent and Trademark Office upheld patents from both parties, returning a decision that Zhang’s patents did not interfere with Doudna’s. Although, this is likely not the end of the CRISPR-Cas9 patent battle. The Doudna group still can appeal the USPTO decision, which will give them another opportunity to attempt to take down the Zhang patent. Likewise, in Europe, this patent battle is continuing, with no decision made yet by the European Patent Office.

What does the USPTO decision mean for innovation and patients?

While the successful treatment of genetic disease with gene therapy is still years into the future, the versatility of the CRISPR-Cas9 system has advanced progress in the field remarkably. It has considerable promise for use in gene therapy and has already been approved for use in human trials in the treatment of cancer[4]. The USPTO decision to allow the Zhang lab to keep their patents means that companies wanting to adopt the technology for gene therapy in humans would require licenses for both the Zhang’s and the Doudna’s patents. Having to obtain multiple licenses could considerably increase costs for developing gene therapies using CRISPR-Cas9. Therefore, companies may get discouraged from developing CRISPR-Cas9 for gene therapy due to increased costs and the uncertainty over which party will retain patent rights or if Doudna decides to appeal. Researchers have also been attempting to engineer alternative gene editing systems similar to the CRISPR-Cas9 system. Whether these alternative technologies will be developed before the CRISPR-Cas9 patent battle is settled is uncertain. Ultimately, this decision does end up costing patients because it will either delay the development of gene therapy or increase the cost for patients. If this patent battle has demonstrated anything, it is how even though the current system has been designed to give protection to innovators for their ideas, it can also often delay the creation of those same innovations it wants to encourage.

[1] Yoshizumi Ishino et al., “Nucleotide sequence of the iap gene, responsible for alkaline phosphatase isozyme conversion in Escherichia coli, and identification of the gene product.” online: (1987) 169:12 J. Bacteriology (1987) at 5429-5433 <>

[2] Martin Jinek et al., “A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity.” online: (2012) 337 Science at 816-821 <>

[3] Le Cong et al., ” Multiplex Genome Engineering Using CRISPR/Cas Systems” online: (2013) 339:6121 Science at 819-823 <>

[4] Sara Reardon, “First CRISPR clinical trial gets green light from US panel”, Nature (22 June 2016) online: <>


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