Scientists see promising early results from early studies testing gene editing for painful, inherited blood disorders that affect millions worldwide, especially blacks.
Doctors hope that the one-time treatment that permanently changes the DNA in blood cells using a tool called CRISPR can treat, and potentially cure, sickle cell disease and beta thalassemia.
Partial results were presented at a conference of the American Society of Hematology on Saturday and some were published by the New England Journal of Medicine.
Doctors described 10 patients who were removed from their treatment for at least a few months. All no longer needed regular blood transfusions and were free from the pain that had plagued their lives before.
Victoria Gray, the first patient in the sickle cell study, was in severe pain for a long time, which often took her to the hospital.
« I’ve had aching pains, sharp pains, burning pains, what you call it. It’s all I’ve known all my life, « said Gray, 35, of Forest, Mississippi. « I hurt everywhere my blood flowed. «
Since her treatment a year ago, Gray has weaned herself from pain medication that she relied on to relieve her symptoms.
« It’s something I’ve prayed all my life, » she said. « I pray everyone has the same results as me. «
Sickle cells affect millions, mostly blacks. Beta thalassemia affects about 1 in 100. 000 people. The only cure now is a bone marrow transplant from a closely matched donor without the disease, like a sibling that most people don’t have.
Both diseases involve mutations in a gene for hemoglobin, the substance in red blood cells that carries oxygen around the body.
In sickle cells, defective hemoglobin leads to deformed, sickle-shaped blood cells that do not transport oxygen well. They can stick together and clog small vessels, causing pain, organ damage, and strokes.
People with beta thalassemia do not have enough normal hemoglobin and experience anemia, fatigue, shortness of breath, and other symptoms. In severe cases, transfusions are required every two to five weeks.
In the womb, fetuses produce a special type of hemoglobin. When babies breathe on their own after birth, a gene is activated that instructs cells to switch and make an adult form of hemoglobin instead. The adult hemoglobin is what is defective in people with any of these diseases. The CRISPR machining aims to cut out the Schaltgen.
« What we’re doing is turn that switch back off and make the cells believe they’re back in the womb » so that they can start producing fetal hemoglobin again, said a study director, Dr. . Haydar Frangoul of the Sarah Cannon Research Institute in Nashville.
The treatment involves removing stem cells from the patient’s blood and then using CRISPR in a laboratory to turn off the switching gene. Patients are given powerful drugs to kill their other, faulty blood-producing cells. Then they get their own laboratory-modified stem cells back.
Saturday’s results were for the first 10 patients, seven with beta thalassemia and three with sickle cells. The two studies in Europe and the US are ongoing and will each include 45 patients.
Tests to date suggest that gene editing is working as intended with no unintended effects, Frangoul said.
The study was sponsored by therapy manufacturers CRISPR Therapeutics, headquartered in Zug, Switzerland, and Vertex Pharmaceuticals, based in Massachusetts. Some study leaders advise for the company.
Dr. . David Williams of Boston Children’s Hospital at Harvard announced partial results of a study that tested a novel gene therapy that is also intended to restore the production of fetal hemoglobin in sickle cells.
Six patients, including one in 7, received treatment that involved removing some of their blood stem cells and changing them in the laboratory to attenuate the hemoglobin switching gene. None of them had pain crises, five of the six no longer need transfusions and all of them have almost normal hemoglobin, he reported at the conference and in the medical journal.
Government grants for work. Williams is named for a patent for the therapy that Boston Children’s gave to Bluebird Bio Inc. Has licensed. from Cambridge, Massachusetts. The company provided the therapy for the study, which will involve a total of 10 people, to ensure safety. A larger study to test the effectiveness is planned.
Williams, who was not involved in Frangoul’s study, said he « validates this approach » to target the hemoglobin switching gene against sickle cells.
Sickle Cell Disease, Cell, Gene Therapy, Medicine, Hematological Disease, Hematology
World News – AU – Genetic Editing Treatment Shows Promise for Sickle Cell, Other Blood Diseases
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