Scientists are hoping to permanently change a person’s DNA to cure a disease. This is the first time they have tried editing a gene inside the body.
The lucky recipient of this new trial is 44-year-old Brian Madeux who has Hunter syndrome. Madeux through an IV will receive billions of copies of a corrective gene and a genetic tool to cut his DNA in a precise point.
Madeux says “It’s kind of humbling” to be the first patient to test this. “I’m willing to take that risk. Hopefully, it will help me and other people.”
Scientists have edited genes previously, altering cells in the lab and returning it to the patient. The effects of this type of therapy were only temporary. Another problem with the previous method is that scientist couldn’t control where it inserts in the DNA, sometimes causing new issues like cancer.
This new method is more precise and permanent.
“We cut your DNA, open it up, insert a gene, stitch it back up. Invisible mending,” said Dr. Sandy Macrae, president of Sangamo Therapeutics, the California company testing this for two metabolic diseases and hemophilia. “It becomes part of your DNA and is there for the rest of your life.”
“You’re really toying with Mother Nature,” said one independent expert, Dr. Eric Topol of the Scripps Translational Science Institute in San Diego. The effects are permanent, but the trials are necessary because these are incurable diseases.
People die at such a young age there are less than 10,000 who have these metabolic diseases. With Madeux’s condition, Hunter syndrome, he lacks a gene that creates an enzyme that breaks down certain carbohydrates which causes problems throughout the body.
The therapy has three parts: The new gene and two zinc finger proteins. DNA instructions for each part are placed in a virus that’s been altered to not cause infection but to ferry them into cells. Billions of copies of these are given through a vein.
They travel to the liver, where cells use the instructions to make the zinc fingers and prepare the corrective gene. The fingers cut the DNA, allowing the new gene to slip in. The new gene then directs the cell to make the enzyme the patient lacked.
Only 1 percent of liver cells would have to be corrected to successfully treat the disease, said Madeux’s physician and study leader, Dr. Paul Harmatz at the Oakland hospital.
Madeux has had 26 operations for hernias, bunions, bones pinching his spinal column, and ear, eye, and gallbladder problems.
For Madeux weekly IV doses of the missing enzyme can ease some symptoms, but cost $100,000 to $400,000 a year and don’t prevent brain damage.
“It seems like I had a surgery every other year of my life” and many procedures in between, he said. Last year he nearly died from bronchitis and pneumonia attack. The disease had warped his airway, and “I was drowning in my secretions, I couldn’t cough it out.”
Gene editing won’t fix the damage he’s already suffered, but he hopes it will stop the need for weekly enzyme treatments.
Initial studies will involve up to 30 adults to test safety, but the ultimate goal is to treat children very young before much damage occurs.