Fetal Stem Cell Therapy Trial for Brittle Bone Disease

Dr. Cecilia Gӧtherström works as a medical researcher at the Karolinska Institutet in Stockholm, Sweden. Earlier this month, Dr Gӧtherström announced the commencement of the first clinical trial that utilizes fetal stem cell transplants to treat the brittle bone disease, Osteogenesis Imperfecta.

Osteogenesis imperfect (OI) was made famous by the Bruce Willis/Samuel Jackson movie “Unbreakable.” In this movie, Samuel Jackson played a wheel-chair bound savant whose bones were incredibly fragile, but acted as a mentor to Bruce Willis’ character who had a tendency to not become injured despite being in accidents and other traumatic events. Willis becomes a kind of local protector of the weak and innocent in his community under Jackson’s tutelage. I will not give away the surprising ending, but the fact that Jackson’s character had OI and his bones broke so easily put OI in the public’s consciousness.

OI is actually a group of genetic disorders that affects an estimated 6 to 7 per 100,000 people worldwide and prevents the bones from forming properly. This disease results from mutations in the COL1A1, COL1A2, CRTAP, and P3H1 genes. More than 90 percent of all cases of OI result from mutations in the COL1A1 and COL1A2 genes. The COL1A1 and COL1A2 genes encode the type I collagen proteins. Collagen is the most abundant protein in bone, skin, and other connective tissues. Patients with OI have fragile bones that break easily, sometimes with no apparent cause. OI can also cause loose joints, fatigue, early hearing loss, and respiratory problems. Multiple fractures are common, and in severe cases, can occur even before birth. Milder cases may involve only a few fractures over a person’s lifetime.

The publication SelectScience interviewed Dr. Gӧtherström who is the coordinator of this clinical trial that will use stem cell therapy to treat babies diagnosed with OI before they are ever born. Dr Gӧtherström told SelectScience that she and her colleagues selected OI as a disease to attack with stem cell treatment because “no good treatment exists.” Dr. Gӧtherström continued: “OI is a chronic disorder that affects the patient throughout their lifetime with reduced quality of life.” Also, because OI causes poor bone mineralization, fractures and malformation of the bones commences by the time the baby is born. Therefore, physicians can diagnose OI during pregnancy, and once it has been diagnosed, it is crucial to initiate treatment as soon as possible.

Dr. Gӧtherström and her colleagues will infuse stem cells into the fetal bodies of babies afflicted with OI by employing the same protocol that is generally used for blood transfusions during pregnancy. This is a very well-tested technique that carries a very little risk to the mother and her baby. According to Dr. Gӧtherström, there is a theoretical risk of the donor cells acquiring mutations that causing cancer in the mother, but this is very unlikely.

Fetal stem cell therapy has some benefits over other types of stem cell therapy. According to Dr. Gӧtherström, “Fetuses do not have a fully developed immune system, so the donor cells may have a better engraftment potential.” Also, fetal Mesenchymal Stem Cells (MSC) have a far better ability to form bone tissue than adult stem cells.

“If this proves to be safe and efficient, we will explore other disorders that can be treated prenatally, such as other skeletal dysplasias, or metabolic disorders,” Dr Gӧtherström explained. The success of this trial could open up new avenues for prenatal therapies to become more common. Dr. Gӧtherström believes that prenatal diagnosis of similar chronic disorders will shift, from delaying or slowing down the onset of a condition to actually treating it.