Doctors working with the gene-editing tool CRISPR have made a giant leap by virtually undoing sickle cell disease in a 34-year-old Mississippi woman born with the genetic blood disorder. More work needs to be done, but it’s a promising development in the decadeslong fight against this and possibly other diseases.
Victoria Gray hasn’t had a blood transfusion for about a year, and she’s off all the pain medication she once took for the debilitating disease, which impairs the ability of blood cells to carry oxygen.
As with all ongoing medical trials, researchers remain circumspect. But the apparent success of CRISPR therapy in Ms. Gray’s case is backed up by similar trials in which two people with beta thalassemia, a related condition, have been mostly relieved of symptoms.
Dr. Haydar Frangoul, who has been treating Ms. Gray at the Sarah Cannon Research Institute in Nashville, Tenn., told NPR he was excited but cautious.
“It’s too early to celebrate,” he said, “but we are very encouraged so far.”
CRISPR has the potential to erase some genetic diseases, perhaps even some forms of blindness. It also shows promise in treating cancers, AIDS, cystic fibrosis, heart disease and other incurable maladies, including new infectious diseases. It also may help in applications in which stem cells are used to repair or replace damaged tissue and organs.
Researchers at Stanford University are using CRISPR to develop a way to inhibit coronaviruses. In May, the Food and Drug Administration fast-tracked a CRISPR-based test with the potential to diagnose COVID-19 in about an hour.
In Ms. Gray’s case, the therapy was complicated and arduous. But Dr. Francis Collins, director of the National Institutes of Health, told NPR the results were “both enormously exciting for sickle cell disease and for all those other conditions that are next in line.”
Doctors took some of her bone marrow cells, edited a gene inside them to produce fetal hemoglobin to better carry oxygen, then transfused some 2 billion modified cells back into her body.
Now, about half of her hemoglobin is fetal hemoglobin — a better than expected result — and there have been no adverse side effects so far. It’s not a cure technically, and doctors don’t know if it will prove to be a lifelong benefit. But it has relieved Gray of most of her symptoms, something Dr. Frangoul called a “functional cure.”
More human trials are in the pipeline. Undoing the effects of sickle cell disease alone would be a major breakthrough. About 1 in every 365 African Americans is born with the disease, and most victims die young from complications. Until now, bone marrow transplants have been the only way of effectively treating a small percentage of people afflicted.
CRISPR technology, however, could open a new era in medicine and in medical ethics. Time will tell.
What’s important to Ms. Gray is that she is back home with her husband and three children and living life more normally than she ever has. That alone is worth celebrating.