The University of Pennsylvania confirmed for the first time that two US patients had been treated using CRISPR gene editing.
Several other human trials of CRISPR are starting or are set to start in the US, Canada and Europe to test CRISPR’s efficacy in treating various diseases.
The work removes immune system cells from patients, genetically modifying them in the lab and infusing the modified cells back into the body. Gene edited t-cells to fight cancer has been performed extensively using zinc finger gene therapy.
Sangamo Therapeutics has been developing Zinc finger nuclease (ZFN) autologous and allogeneic gene-edited cell therapies for blood disorders including beta-thalassemia and sickle cell disease, immunological disorders, as well as various types of cancer. Sangamo has been studying zinc finger nucleases for over 20 years and is the primary patent holder for this technology. CRISPR gene-editing emerged in 2013.
The primary criticism of zinc finger nucleases as a gene-editing tool is the time and skill it takes to develop a high-quality gene snipping product compared with CRISPR. Sangamo has shortened the development timeline for zinc finger nucleases.
CRISPR is less flexibility for target any gene sequence. Target gene sequence for CRISPR must be immediately upstream of a protospacer adjacent motif (PAM). Zinc fingers have no restriction of that type.
CRISPR is much faster and cheaper to work with in the lab.
Two CRISPR trials sponsored by CRISPR Therapeutics and Vertex Pharmaceuticals are designed to treat genetic blood disorders. One is for sickle cell disease, and another is a similar genetic condition called beta thalassemia.
Editas Medicine will try to treat an inherited form of blindness known as Leber congenital amaurosis. Editas will try to edit genes inside the human body.