Scientists in London have developed, and now used, a new kind of biological scissor in a desperate effort to cure a child with otherwise untreatable leukemia. They used the revolutionary medical tool to edit the genes in immune cells, programming them to hunt down and destroy the malignant blood cells that threatened the young girl’s life.
While the experimental procedure was completed in June, news of the groundbreaking operation was made public yesterday. The hospital said it was the first time that a genome-editing technology called TALEN had been used to treat a patient.
TALEN is one of three genome-editing tools that scientists and companies are racing to test in humans. Developers and medical professionals see the tool as not only an aid against cancer, but as possible treatments for everything from cystic fibrosis to sickle cell disease, to even Huntington’s disease.
Another gene-editing tech, named zinc fingers, is already in a clinical trial for AIDS sponsored by California-based biotech Sangamo BioSciences.
“I think it’s great,” Sangamo president Edward Lanphier said of the London cancer case. “It’s further demonstration of the ability to use genome-editing technologies in patients.”
Doctors were forced into action for this particular case; Layla had received chemotherapy for her acute lymphoblastic leukemia after it was diagnosed in September 2014. But her leukemia manifested into what doctors called one of the most aggressive forms of the disease they had ever seen, and she relapsed within seven weeks.
They considered other unusual techniques, but her lack of immune cells halted any alternative treatments. So they went with the only option available to them: the TALEN editing tool. They used TALEN to restructure the genomes of the donor cells in two specific ways: cutting out genes that made them vulnerable to a powerful leukemia drug that would otherwise kill them , and inserting genes to make the donor T cells target the specific antigens on her tainted blood cells.
“The approach was looking incredibly successful in laboratory studies, and so when I heard there were no options left for treating this child’s disease, I thought, ‘Why don’t we use the new [cells]?’” gene therapy researcher Waseem Qasim of University College London said in a statement.
Tests showed her leukemia was responding well to the man-made cells. She got better after a few weeks; she was then ready for a bone marrow transplant. And now? She’s recovering well at home, according to the hospital.
“We have to be cautious about claiming that this will be a suitable treatment option for all children,” Qasim warned.
“But this is a landmark in the use of new gene-engineering technology that, if replicated, could represent a huge step forward in treating leukemia and other cancers.”
Cellectis, the French company that created the TALEN technology, plans to test its off-the-shelf engineered immune cells against leukemia in a clinical trial starting early next year.