The challenge for the first ever in-human gene editing trial, according to today’s guest, is with the delivery to the body.
“At the moment, the easiest place to deliver your gene or genome editing is to the liver, using AAV which are viruses that seek out and go to the liver cells," says Sandy Macrae, the CEO of Sangamo Therapeutics.
Sangamo is known for two things: They have pioneered the commercialization of an older gene editing technology called Zinc Fingers. And they have done a lot of work in the area of HIV.
Today, Sangamo is enrolling patients in a new trial which they say will be the first "in-vivo" trial using their Zinc Fingers for patients with hemophilia B, Hunter syndrome, and Hurler syndrome. The former gene editing work with the T cells of HIV patients, Sandy says, was done “ex-vivo”, or outside the body.
So why is Sangamo still using Zinc Fingers in the age of CRISPR? Sandy says that the older technology is much better developed for medical applications and is safer. The company has been able to get their off target effects to below the level of detection.
“When I was doing my postdoc, I would have used CRISPR. It’s better if you’re just wanting an easy experiment that isn’t about making a medicine but just getting a quick answer,” he says.
Because Sangamo has been the sole commercial developer of Zinc Fingers with not a lot of intellectual property dispute, the technology didn’t make the big PR splash that CRISPR has—nor, at the same time, did it generate all the fear.
We finish the interview with a question about what was the result of all Sangamo's work in HIV over the years.