New treatment giving hope to blood disorder patients
Published: 19 April 2018 Image credit: Reuters
In a major breakthrough, researchers have found experimental gene therapy could reduce or eliminate the number of blood transfusions needed by people with an inherited blood disorder known as Beta-thalassemia.The landmark study, published in the New England Journal of Medicine (NEJM), involved two early clinical trials and 22 patients, with a third phase of the trial currently underway.
The early trials evaluated the safety and efficacy of the gene therapy by using LentiGlobin, an experimental treatment developed by biotech company Bluebird Bio.
During the trial, the study found that 15 of the 22 patients who had the disease and underwent gene therapy were either able to reduce or eliminate the need for blood transfusions.
Of the 13 patients who had a less severe form of the disease, only one was able to stop receiving blood transfusions entirely.
Three of nine patients who had a more severe form of the disorder were able to stop transfusions completely while the rest were able to reduce their frequency.
The treatment was tested on patients from the United States, Australia, and Thailand.
During the trial, doctors followed patients’ progress for up to three years.
Researchers reported there were no severe side effects from the gene therapy, and no unexpected safety issues.
However, more research is needed to evaluate how effective the treatment is and how safe.
Researchers say they will continue to monitor patients for any long-term risks.
However, Bluebird Bio, in Cambridge, Massachusetts plans to seek approval of the treatment in Europe by the end of the year.
According to reports, an estimated 288,000 people worldwide have the genetic disorder known as Beta-thalassemia.
It’s an inherited blood disorder caused when the body doesn't make enough of a protein called Hemoglobin, an essential part of red blood cells.
The disease is caused by a mutation in this gene that impairs the ability of red blood cells to carry oxygen to tissues in the body.
Patients must undergo blood transfusions, allowing new blood cells to supply oxygen to body tissues and enabling patients to live relatively healthy lives.
However, transfusions can cause complications including the build-up of dangerous levels of iron in the body.
The experimental gene therapy allows people with the blood disorder to become independent of transfusions by replacing the defective genes in the stem cells of bone marrow.
The therapy involves extracting blood stem cells from a patient’s bone marrow and modifying them outside the body with a virus that carries a correct copy of the gene, which makes Hemoglobin.
Patients receive chemotherapy to remove the blood stem cells with defective genes from their bodies, and then the modified stem cells are infused back into the patient’s marrow to produce healthy blood cells.
The treatment is a significant breakthrough and milestone for the biotech company, and the latest in a string of successes for gene therapies, which aim to modify a person’s DNA to treat disease.
The company is also developing gene therapies for Sickle-cell disease and Childhood Cerebral Adrenoleukodystrophy, also known as Lorenzo’s Oil disease, which affects a person’s nervous system.
In 2017, the company reported that a French boy who had received its gene therapy for Sickle-cell now has no symptoms of the disease.