Gene Therapy cures sickle cell in teenage boy
- Author: Joanne Flowers Mar 04, 2017,
Mar 04, 2017, 22:36
A French teen who underwent a first-of-its-kind procedure 15 months ago to change his DNA shows no signs of the sickle cell disease he had been suffering from. "At the same time, what we've observed is really convincing, and we just hope that we can move this along to make it available to patients". The Philippe Leboulch was carried out at Necker Children's Hospital in Paris, France.
Finally, Dr. Grace Onimoe of the American Sickle Cell Anemia Association noted that the life expectancy of a patients with sickle cell disease remains decades lower than that of the general population while children throughout the world continue to suffer. "Doing it with older patients, who have had years of complications, could be more challenging".
"This is not right around the corner", said Dr. George Buchanan, a professor emeritus of pediatrics at the University of Texas Southwestern Medical Center in Dallas.
"This is what people have been wanting and waiting for", he said. But early success in treating sickle cell disease means that soon, if we're lucky, the benefits of this technology may reach hundreds of thousands of people. About one in every 365 black children in the United States is born with sickle cell disease, for which the life expectancy is now about 40 to 60 years.
It arises when a person inherits two copies of an abnormal hemoglobin gene - one from each parent.
Sickle cell disease is an inherited blood disease that affects hemoglobin, the component of red blood cells responsible for delivering oxygen to other cells all over the body. In a paper published Thursday in the New England Journal of Medicine, the researchers revealed that today, half of his red blood cells have normal-shaped hemoglobin.
These deformed cells can lock together to block the flow of blood around the body.
This leads to "tremendous pain, anemia and also lesions of organs that ultimately result in shortness of life expectancy", Leboulch said.
There are treatments for sickle cell, such as some cancer drugs, Buchanan pointed out, but they can be hard to manage and have side effects. The news is especially encouraging because the patient has been producing normal blood cells despite no longer taking medications or regular blood transfusions.
In a world first, doctors at Necker Children's Hospital removed his bone marrow and genetically altered it using a virus to compensate for the defect in his DNA responsible for sickle cell disease, BBC News reported. He no longer requires a transfusion so we are quite pleased with that. "But most patients don't have a donor".
This single-letter mutation makes it a promising candidate for cutting edge technologies, like the gene-editing technique CRISPR-Cas9, and other gene therapies.
For sickle cell disease, a companion trial in the U.S. is underway.
The corrected bone marrow was then put back into the patient. Finally, they returned the treated stem cells via an IV into his bloodstream.
Over the next few months, the boy showed a growing number of new blood cells bearing the mark of the anti-sickling gene.