In October last year, a team of UC Berkeley scientists reported a new, nonviral CRISPR-delivery system that might address safety concerns with the gene-editing technology. Now, their company, GenEdit, has picked up $8.5 million in seed funding to develop their nanoparticle system.
Data Collective Bio and SK Holdings led the financing, joining GenEdit's existing backers, Sequoia Capital and Bow Capital.
GenEdit launched in 2016 and created a nonviral, nanoparticle delivery vehicle for CRISPR. The next year, GenEdit’s founders, along with colleagues from UC Berkeley and a few institutions in Japan, detailed a gold nanoparticle-based vehicle that successfully delivered a treatment to mouse models of Duchenne muscular dystrophy. The treatment, dubbed CRISPR-Gold, corrected the mutated dystrophin gene in the mice and restored the expression of the dystrophin protein in the mice’s muscle tissue.
The company is going after a nonviral vector because adeno-associated viruses (AAVs)—currently the most advanced method to deliver CRISPR—still come with challenges. For one, they allow the Cas9 enzyme to remain in the cell after editing is complete.
Even after editing is complete, the Cas9, or CRISPR “scissors,” will be “chewing up” parts of the genome, which can cause mutations, said Niren Murthy, a professor of bioengineering at UC Berkeley and a cofounder of GenEdit, last year.
Another problem is that the viruses are too small to fit all three CRISPR ingredients—Cas9, a guide RNA and donor DNA—so multiple viruses must be used to deliver the treatment. And here's one more: Patients could have preexisting immunity to AAVs, which would disqualify them as candidates for treatment, said GenEdit CEO and cofounder Kunwoo Lee.
Since its work on CRISPR-Gold, GenEdit has expanded its reach into other disease areas, including autism. Researchers reported in June that CRISPR-Gold was able to deliver editing to the brain and change the behavior of mice with Fragile X syndrome, the most common known single-gene cause of autism spectrum disorder. The treatment edited the gene for a neurotransmitter receptor and reduced the repetitive behavior that is characteristic of Fragile X. GenEdit has also published work on using a new polymer-based system—with no gold in it—to deliver a different CRISPR enzyme: Cas12a.
Since launch, GenEdit has been building its stable of polymer nanoparticles with different structures, compositions and surface charges, Lee said. It’s creating a library of hundreds of polymers because different polymers may work better in different types of tissue. For example, a polymer that works well in the muscle may not work as well in the brain.