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The powerful gene editing technique called CRISPR has been in the news a lot. And all the news is not good: a Chinese scientist surprised the world last year by announcing that he had used CRISPR to create genetically modified babies.
But scientists have long hoped that CRISPR – a technology that allows scientists to make very precise modifications to DNA – could eventually help cure many diseases. And now, scientists are taking concrete first steps to make this dream a reality.
For example, NPR has learned that a US CRISPR study that had been approved for cancer at the University of Pennsylvania in Philadelphia had finally begun. A university spokesman confirmed for the first time Monday that two patients had been treated with CRISPR.
One patient had multiple myeloma and another had sarcoma. Both had relapsed after suffering standard treatment.
The revelation comes as several other CRISPR trials in humans begin or will soon begin in the US, Canada, and Europe to test the efficacy of CRISPR in the treatment of various diseases.
"2019 is the year when the training wheels stand out and the whole world sees what CRISPR can really do for the world in the most positive sense," says Fyodor Urnov, gene editing scientist. at the Altius Institute for Biomedical Sciences, Seattle. and the University of California at Berkeley.
Here are the highlights of the coming year in CRISPR research and answers to common questions about technology.
Remind us what exactly is CRISPR?
CRISPR is a new type of genetic engineering that gives scientists the power to modify DNA much more easily than ever before. Researchers believe that CRISPR could revolutionize the way they prevent and treat many diseases. CRISPR could, for example, allow scientists to repair genetic abnormalities or use human cells genetically engineered as therapies.
Traditional gene therapy uses viruses to insert new genes into cells to treat diseases. CRISPR treatments largely avoid the use of viruses, which have already caused security problems. Instead, they directly modify the DNA using targeted molecular tools. The technique was compared to the cut-and-paste function in a word processing program. It allows scientists to eliminate or modify specific problematic genes.
Is this the same technique that caused a recent scandal when a scientist in China altered the genes of two human embryos?
There is an important difference between the medical studies under discussion here and what Chinese scientist He Jiankui did. He used CRISPR to edit genes for human embryos. This means that the changes he brought would be passed on to future generations. And he did it before most scientists think it was safe to try. In fact, calls have been made for a moratorium on the genetic modification of hereditary traits.
For medical treatments, only the DNA of each patient is changed. Therefore, this genetic modification does not give rise to any dystopian fear about the re-engineering of the human race. And there has been a lot of careful preparation for these studies to avoid unintended consequences.
So what's going on now with the new or planned trials?
We have finally arrived when CRISPR leaves the laboratory to go to the clinic around the world.
Until now, only a relatively small number of studies have tried using CRISPR to treat a disease. And almost all of these studies were conducted in China and were aimed at treating various forms of cancer.
An ongoing clinical trial at the University of Pennsylvania uses CRISPR for the treatment of cancer. This involves removing cells from the immune system of patients, genetically modifying them in the laboratory and injecting the modified cells back into the body.
The hope is that the modified cells will target and destroy the cancer cells. No other information has been disclosed about its potential effectiveness. The study was approved to possibly treat 18 patients.
"The results of this research study will be communicated at an appropriate time via a medical meeting presentation or a peer-reviewed publication," wrote a university spokesperson in an email to NPR.
But beyond the cancer study, researchers from Europe, the United States and Canada are launching at least half a dozen carefully designed studies to use CRISPR to treat a variety of diseases.
What other diseases are they testing for?
Two trials sponsored by CRISPR Therapeutics of Cambridge, Massachusetts, and Vertex Pharmaceuticals, of Boston, have been designed to treat genetic disorders of the blood. One is about sickle cell disease and the other a similar genetic disorder called beta-thalassemia.
In fact, the first patient with beta-thalassemia has recently been treated in Germany. More patients may soon be tested for CRISPR blood cells at this hospital and at a second clinic in Germany, followed by patients at medical centers in Toronto, London and possibly elsewhere.
The first patients with sickle cell disease may soon begin to receive DNA from their blood cells in this country, in Nashville, Tennessee, San Antonio, Texas and New York.
And yet another study, commissioned by Editas Medicine, Inc. of Cambridge, Mass., Will attempt to treat a form of hereditary blindness known as Leber's congenital amaurosis.
This study is remarkable because it would be the first time that scientists have tried to use CRISPR to edit genes while they are inside the human body. The other studies involve removing cells from patients, modifying the DNA of these cells in the laboratory, and then reinjecting the modified cells into the patients' bodies.
Finally, several other US studies on cancer could also start this year in Texas, New York and elsewhere to try to treat tumors by genetically modifying the cells of the immune system.
What's wrong with CRISPR? Are there any concerns?
Whenever scientists try something new and powerful, it always raises fears that something is wrong. The beginnings of gene therapy have been marked by major setbacks, such as the case of Jesse Gelsinger, who died after an adverse reaction to a treatment.
The major problem with CRISPR is that the revision may go wrong, leading to unintentional changes in the DNA that can cause health problems.
This new wave of studies is also a cause for concern because it is the first to be approved without a more thorough review by the National Institutes of Health. This is because the NIH and FDA have changed their policy, stating that only some studies would require this additional step of review.
"All humans on the planet should hope this technology works, but it could work, it might not be, it's unknown," said Laurie Zoloth, a bioethicist at the University. from Chicago. "It's an experience. So you need quality care. And you really have to think ahead of time by doing a thorough ethical review of how you do this type of work. "
The researchers who conducted the studies claim to have conducted extensive preliminary research and that their studies have been the subject of thorough scientific and ethical scrutiny.
When could we know if any of these experimental CRISPR treatments are effective?
All of these studies are very preliminary and are mainly aimed at checking if this is safe. That said, they are also looking for clues to find out if they could help the patients. So there could be at least one clue about it later this year. But it will take many years before any CRISPR treatment becomes widely available.
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