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The powerful gene editing technique known as CRISPR has raised much hope in recent years for its potential to offer new ways of treating many diseases, including cancer. But so far, scientists have released very little information on test results in patients.
On Wednesday, researchers uncovered data from the first study involving cancer patients in the United States who received cells genetically modified with CRISPR.
The expected results, while quite preliminary, seem hopeful, say scientists.
"This is a very important first step," says Dr. Edward Stadtauer, professor of oncology at the University of Pennsylvania and principal investigator on the study. "We hope this is the beginning of the next generation of engineered cells that will help many different diseases and many different tumors."
Stadtmauer emphasizes that the process is not designed to determine whether the approach actually works – only whether it is safe and feasible.
"This treatment is not ready for the first time," he says. "But it's definitely very promising.
Other researchers agree.
" I'm just so excited about it, "says Jennifer Doudna of UC Berkeley, who contributed to the discovery and development of CRISPR
." an important step towards using CRISPR-Cas for genome editing in patients and demonstrating the potential of this technology to be safe and effective therapy, "says Doudna.
Dr. Michel Sadellin, who does related research at the Memorial Center about Metin Kettering's cancer in New York, says h is glad that gene editing is being moved to the clinic that way, although she emphasizes that patients will have to be followed for much longer to gain confidence, the approach is really safe.
"I don't think there is still a lot to conclude, "Sadelain says." We will want more patients and longer follow-up to really say that using CRISPR is safe. But the data is certainly encouraging. So far, so good – but still early. "
China has been trying for years to use CRISPR to treat cancer patients, but has released very little information about their work.Another American study including CRISPR for cancer has recently begun to recruit patients.
All studies are part of the first wave from research moving CRISPR out of the lab Doctors have just begun testing CRISPR for heart disease and beta thalassemia, and scientists are planning to soon try to use CRISPR to edit cells in the human body as a way to treat a genetic form of blindness.  The cancer study, which will be presented next month at a meeting of the American Hematology Society in Orlando, Flag., Involved only three patients – two with multiple myeloma and one with sarcoma.
Patients received infusions of about 100 million cells from their own immune system, which were removed from their bodies and genetically modified in a laboratory.
Stadtmauer says the approach aims to combine CRISPR, a technique that allows scientists to make very accurate DNA changes much easier than ever before, with another of the most exciting advances in medical research in recent years – involvement of the immune system in the fight against cancer.
"The last decade has really been a revolution in cancer immunotherapy," says Stadtower. "We really learned how to harness the immune system to treat cancer – to create those miraculous cells that infuse patients as living cancer drugs."
While this approach has created new treatments for some patients with leukemia and lymphoma , these genetically engineered live drugs either do not work for many cancer patients or eventually stop working.
This prompted scientists to turn to CRISPR.
"We want to see if we can even improve these results by giving these cells something like superpowers to multiply even better, stay better with patients as live medicines, and potentially attack even more directly to the tumor, "says Stadtmauer.
Scientists use CRISPR to knock out three genes in cells to allow cells to attack cancer cells more aggressively. They also used a more traditional form of genetic manipulation to insert into the cells a gene that would specifically target the patient's cancer cells.
Patients were treated in January, April, and August, with the first patient followed for at least six months. The cells appear to be doing what scientists hoped to do without causing any significant adverse effects, the researchers said.
The next step, they believe, is to treat additional patients as part of a trial that will ultimately include 18 participants who have sarcoma, melanoma or myeloma.