In a first, oncologists and geneticists have edited a patient’s own immune cells using CRISPR and injected them as a treatment for an aggressive form of lung cancer.
The trial, conducted at West China Hospital in Chengdu, is the first of what is expected to be many that will test the safety of using the gene editing technique to alter a person’s cells. U.S. trials are expected to begin in early 2017.
Both studies will employ what are essentially advanced forms of immunotherapy, where doctors modify cells from a patient’s immune system to attack cancer cells. Because the cells involved are not a part of the reproductive system, their edited genomes cannot be passed on to any children the patients may have after the treatment.
The patient involved in the Chinese study has been unsuccessfully treated for metastatic non-small-cell lung cancer, an aggressive form of the disease that’s often quickly fatal. The person received the first injection of CRISPR-edited cells on October 28.
David Cyranoski, reporting for Nature News, has more details on the procedure:
The researchers removed immune cells from the recipient’s blood and then disabled a gene in them usingCRISPR–Cas9 , which combines a DNA-cutting enzyme with a molecular guide that can be programmed to tell the enzyme precisely where to cut. The disabled gene codes for the protein PD-1, which normally puts the brakes on a cell’s immune response: cancers take advantage of that function to proliferate.
The edited cells were then injected into the patient. Doctors hope the new cells will be able to exploit their PD-1 mutation to seek out and kill the cancer cells. It’s still too early to tell if the effort was safe or successful.
If the patient shows no ill effects, the plan is to administer a second injection. Eventually, ten patients enrolled in the study will receive up to four injections.
While scientists are optimistic about CRISPR’s broader potential in medicine, they’re less certain about whether this particular trial will be more effective than existing immunotherapies, which use modified proteins called antibodies that are easier to make in the lab than CRISPR-edited immune cells.