Doctors say they developed a personalized gene editing therapy in less than seven months and used it to treat a baby with a fatal metabolic condition.
The fast-track attempt to correct the child’s DNA marks the first time genome editing has been adapted to treat a single individual, according to a report published in the New England Journal of Medicine.
The treated child, Kyle “KJ” Muldoon Jr., suffers from a rare metabolic condition caused by a rare error in the genetic code.
Researchers say that the attempt to correct the error demonstrates high accuracy of the new genetic editing tools.
“I don’t think I’m exaggerating when I say this is the future of medicine,” says Kiran Musunuru, a gene editing specialist at the University of Pennsylvania (USA), whose team designed the drug. “My hope is that, one day, no patient with rare disease will die early due to errors in their genes, because we will be able to correct them.”
The project also highlights what some experts call a growing crisis in genomic editing technology. This is because, although technology can cure thousands of genetic conditions, most of them are so rare that companies would never be able to recover the costs of developing a treatment for them.
In the case of KJ, the procedure was programmed to correct a single letter of DNA in its cells.
“In fact, this drug will probably never be used again,” says Rebecca Ahrens-Nicklas, a doctor at Philadelphia Children’s Hospital, who treats metabolic diseases in children and led the overall effort to treat the child.
This effort involved more than 45 scientists and doctors, in addition to pro bono assistance from several biotechnology companies. Musunuru says he can’t estimate how much it cost in time and effort.
Eventually, he says, the cost of personalized gene editing therapies may be similar to that of liver transplants, which cost about US$ 800,000 (about R$ 4,569,560.00), not including medical care and lifelong medicines.
The fast-track attempt to correct the child’s DNA marks the first time genome editing has been adapted to treat a single individual, according to a report published in the New England Journal of Medicine.
Previous versions of CRISPR were generally used to delete genes, not to rewrite them to restore their function.
The researchers say they were looking for a patient to treat when they learned about KJ. After his birth in August, a doctor noticed that the baby was lethargic. Tests found that he had a metabolic disorder that leads to the accumulation of ammonia, an often fatal condition without a liver transplant.
In the case of KJ, genetic sequencing showed that the cause was a wrong letter in the CPS1 gene, which prevented the production of a vital enzyme.
The researchers approached KJ’s parents, Nicole and Kyle Muldoon, with the idea of using gene editing to try to correct the baby’s DNA. After they agreed, a race began to design the genomic editing drug, test it on animals and obtain authorization from the FDA (US Regulatory Agency) to treat KJ in a single experiment.
The team states that the boy, who has not yet turned one year old, received three doses of the genetic editing treatment, with progressively increased strength. But it is not possible to know exactly how effective the genetic editor was, because they do not want to perform a liver biopsy, which would be necessary to check if KJ genes have really been corrected.
But Ahrens-Nicklas states that as the child is “growing and thriving”, she believes that the edition was at least partially successful and that he may now have “a milder form of this horrible disease”.
“He received three doses of the therapy without complications and is showing some early signs of benefit,” she says. “It is very important to say that it is still very early, so we will need to continue watching KJ closely to fully understand the effects of this therapy.”
The case suggests a future in which parents would take sick children to a clinic, where their DNA would be sequenced and then quickly receive individualized treatments. Currently, this would only work for liver diseases, for which it is easier to deliver gene editing instructions, but eventually this can also become a possible approach to treat brain diseases and conditions such as muscular dystrophy.
The experiment is drawing attention to a gap between what genomic editing can do and when these interventions are likely to be available to people who need them.
So far, biotechnology companies that test genetic editing are working only on relatively common genetic conditions, such as sickle cell disease, leaving aside hundreds of ultra-rare conditions. Specific therapies, such as the one that helped KJ, are too expensive to be created and approved without a way to recover costs.
However, the apparent success in KJ’s procedure is making the need to find a way forward even more urgent. The researchers recognize that they still do not know how to scale personalized treatment, although Musunuru states that the first steps to standardize the process are already underway at his university and in Europe.
( fontes: MIT Technology Review)
