It has been a momentous month for Stanford researcher Maria Grazia Roncarolo, MD. Following decades of research in Roncarolo's lab and the clinic, pharmaceutical company Glaxo SmithKline has applied for final approval by European Medicines Agency (EMA) of a treatment she developed to cure a deadly childhood immune disorder. If approved by the EMA, which is Europe's equivalent of the U.S. Food and Drug Administration (FDA), the treatment would be the first gene stem cell therapy to be granted approval by a major medical regulatory agency.
The therapy cures a disease called severe combined immune deficiency (SCID), sometimes called the "bubble boy disease," by inserting a gene into blood stem cells and transplanting the stem cells into the patient's body. The treatment is still being evaluated by the FDA.
My greatest satisfaction is that kids who were once incurable now have options
If approved, the treatment will no longer be considered an experimental therapy in Europe, and "people will be able to get this treatment as they would any other, and will be able to get their insurance company to pay for it," Roncarolo told me. The final regulatory review marks the beginning of a new era in which genetically modified stem cells might be used to treat or cure a wide variety of human diseases, she also noted.
Roncarolo developed the treatment while she was scientific director at the San Raffaele Scientific Institute in Milan, Italy. There, she treated kids who were born with an inability to make the enzyme adenosine deaminase (ADA), which leaves them unable to make certain immune cells that protect them from infection. For that reason, children with ADA-SCID are forced to spend their lives in a sterile environment that protects them from infections that most people would easily fight off but are deadly for them.
Roncarolo and her team inserted the gene for ADA into blood stem cells which were transplanted into 18 children with the disease. Once the modified blood stem cells could produce the enzyme, they were able to form the necessary immune cells and the children were able to leave their sterile environment. "Those children have been effectively cured," Roncarolo said.
Other gene therapies have been developed before, but those therapies modified more mature cells that cannot reproduce themselves. Only stem cells can both make more copies of themselves and also produce more specialized cells. If gene therapy is used to modify cells that are not stem cells, the treatment will only last as long as the cells last. Eventually, mature cells age and die, and the disorder returns.
Last year, Roncarolo was recruited to Stanford to continue her work while serving as co-director of the Institute for Stem Cell Biology and Regenerative Medicine. She is busy researching cures for other congenital immune disorders and developing methods that could lead to stem cell treatments for a wide variety of other diseases.
"My greatest satisfaction is that kids who were once incurable now have options," Roncarolo said.
Previously: Countdown to Childx: Stanford expert highlights future of stem cell and gene therapies