In a boost for the field of regenerative medicine, a biotech company has received regulatory approval in Canada for a drug to treat children suffering from graft-versus-host disease, a potentially deadly complication of bone marrow transplantation.
The drug is a preparation of mesenchymal stem cells. These are stem cells that can be extracted from the dental pulp of teeth (also known as dental stem cells) or in this case from bone marrow.
The stem cells are separated out from the marrow and expanded in culture, so that one donation is enough to make as many as 10,000 doses.
Because these are adult stem cells, they do not raise the ethical concerns of embryonic stem cells, whose creation usually involves the destruction of human embryos.
Graft-versus-host disease occurs when the immune cells in a bone-marrow transplant see the recipient’s organs as foreign and attack them, causing potentially severe damage to the skin, liver and digestive tract. This happens most often when the donor is not an exact match for the recipient.
Doctors try using steroids or other drugs to damp the immune attack, but in many cases those don’t work, and the patient may die.
The drug called Prochymal is approved in Canada for children whose condition is not controlled by steroids. According to a small trial, about 60 percent of such children had a clinically meaningful response to the drug.
“Any drug or a cell that has activity in the patients with severe disease is exciting and important,” said Dr. Joanne Kurtzberg, director of the pediatric blood and marrow transplant program at Duke University Medical Center.
Dr. Kurtzberg, said the drug has saved some children’s lives from graft-versus-host disease and could lead to more successful bone marrow transplants.
According to doctors, the Food and Drug Administration indicated that it would require more data before approval, prompting the company to seek approval in Canada first. The company will apparently apply to the F.D.A. later this year.
Stem cells are already used in medicine. Bone marrow or stem cell transplants are used to treat various cancers and genetic diseases. But those transplants are medical procedures, not products sold by a drug company.
Bone marrow transplants require an invasive and painful surgery, both of which can be avoided by banking stem cells when the opportunity presents itself. This is typically done either at birth by banking cord blood and/or when teeth come out naturally or are extracted for things like braces. The dental pulp in teeth are a rich source of mesenchymal stem cells and is fast becoming the affordable option to bank stem cells as a form of bio-insurance.