Rare Diseases: Gene Therapy Developments #4

This is a fourth in a series of Blog Posts on the topic of gene therapy developments for rare diseases.

Gene therapy for rare genetic diseases is hot news in biotechnology. Biotechnology companies that develop and commercialize gene therapy is a rapidly growing field of medicine, especially for rare diseases. Gene therapy involves introducing genes into the body to treat diseases. The objective of gene therapy is to provide genes that correct or supplant the disease-controlling functions of cells that aren’t functioning or doing their job properly.

I – Pompe Disease

Pompe Disease, is a genetic disorder where there is a mutation in a gene that is responsible for the production of an enzyme called Lysosomal Acid Alpha-Glucosidase (GAA). GAA converts stored sugar in the body to glucose. Without this enzyme, the stored sugar in the body, or glycogen, builds up in the muscles leading to weakness that affects the ability to walk and breathe. Children with Pompe Disease are often attached to mechanical ventilators in order to breathe.

A Phase I/II clinical trial at the University of Florida Health, follows 5 patients with Pompe Disease who require mechanical ventilation to breathe. Patients are injected with a “corrective form of the gene using the vector Adeno-Associated Virus Type 1 (AAV-1), a harmless virus that shuttles the gene directly into cells.” Researchers follow the patients for six months with results showing that the gene therapy is safe and improves respiratory function. The Phase I/II results are published in the journal Human Gene Therapy.

Another recent abstract shows that researchers following the patients for the first year of the study, continue to show improvements, depending on how long each participant has been using a ventilator. After gene therapy, some patients are able to breathe on their own for additional minutes, while other patients are able to make it an hour or more without using a ventilator. A co-author of this second abstract, Barbara Smith, P.T., Ph.D., receives an Excellence in Research Award from the American Society of Gene & Cell Therapy.

II – Duchenne Muscular Dystrophy

Another inherited rare disease where gene therapy is showing promise is Duchenne Muscular Dystrophy (DMD). Duke University biomedical engineers recently are able to repair a defect responsible for DMD by using a novel “genetic editing” technique. Instead of the gene therapy approach of adding new genetic material to “override” a faulty gene, researchers at Duke University have developed a way to change the existing mutated gene responsible for the disorder into a normally functioning gene:

“The Duke experiments, which were carried out in cell samples from Duchenne Muscular Dystrophy patients, were made possible by using a new technology for building synthetic proteins known as transcription activator-like effector nucleases (TALENs), which are artificial enzymes that can be engineered to bind to and modify almost any gene sequence. These TALENs bind to the defective gene, and can correct the mutation to create a normally functioning gene.”

The results of the Duke study were published online in Molecular Therapy, the journal of the American Society for Gene and Cell Therapy. The article has open access and is available for a FREE download.

Please Note: “ExRNA Cartoon” National Institute of Health [Public domain] | Wikimedia Commons.

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