It’s been 18 months since the first serious clinical trials of CRISPR gene therapy for two diseases: beta-thalassemia and sickle cell—and all patients so far are having no symptoms at all, neither have they required blood transfusions.
A bone marrow transplant for a donor closely related to the patient has been the only available cure for these diseases before now. However, this option is usually not available for most patients because of difficulties encountered in locating donors that match, complications risks, and the cost.
In the studies, the goal of these researchers is to cure these blood disorders making use of CRISPR/Cas9 gene-editing by raising the production of fetal hemoglobin that produces healthy and normal red blood cells.
The clinical trials have to do with getting stem cells from the patients. These stem cells are edited by the researchers using CRISPR-Cas9 and then these gene-modified cells are infused into the patients. After the infusion, Patients will stay back in the hospital for about a month.
Prior to receiving their modified cells, the seven patients with beta thalassemia required blood transfusions approximately every three to four weeks and the three patients with SCD suffered episodes of severe pain roughly every other month.
All the individuals with beta thalassemia have been transfusion independent since receiving the treatment, a period ranging between two and 18 months.
Similarly, none of the individuals with SCD have experienced vaso-occlusive crises since CTX001 infusion. All patients showed a substantial and sustained increase in the production of fetal hemoglobin.
15 months on, and the first patient to receive the treatment for SCD, Victoria Gray, has even been on a plane for the first time.
Before receiving CRISPR gene therapy, Gray worried that the altitude change would cause an excruciating pain attack while flying. Now she no longer worries about such things.
About her trip to Washington, D.C, Gray told NPR
It was one of those things I was waiting to get a chance to do… It was exciting. I had a window. And I got to look out the window and see the clouds and everything.Gray