A recent article in globenewswire.com news reported that the FDA has approved Fast Track Designation for AMT 130, an experimental gene therapy for the treatment of Huntington’s disease. The Fast Track designation is designed to expedite the FDA’s review of drugs that treat urgent medical needs.
The announcement was made by uniQure N.V., a company that specializes in gene therapies. AMT 130 therapy was developed by uniQure for the treatment of Huntington’s disease.
About The Therapy
AMT 130 has the distinction of being the only adeno-associated viral gene therapy to date to be clinically tested in relation to Huntington’s disease. uniQure plans to begin a Phase 1/2 clinical trial of AMT 130 in 2019.
Adeno-associated virus (AAV)-mediated gene therapy has gained momentum in the treatment of many diseases as well as in the treatment of cancers. AAV is perhaps used more often than most other therapies partly because of its overall superiority to other gene therapies and also because it is not harmful to humans. Additional information about AMT 130 is available here.
About Huntington’s Disease (HD)
Three to seven people per 100,000 are affected by Huntington’s disease. This neurological disorder affects adults between 30 to 40 years of age. Juvenile Huntington’s is relatively rare and tends to develop at a much faster rate.
The HD gene is dominant. There is a fifty-fifty chance of a child inheriting the disease from an HD parent. Only one gene copy of an abnormal gene from one parent is needed for the child to develop HD. Approximately 75,000 people are carriers of the gene with about 35,000 people exhibiting its symptoms.
HD patients may survive ten to fifteen years after being diagnosed with the disease and once its symptoms become obvious. Currently, there are no approved therapies to treat the disorder. Additional information about Huntington’s disease is available here.
The Cause
An abnormal gene is responsible for the development of HD. The HD gene was first isolated on chromosome 4 by scientists in 1993. The scientists discovered that the gene provides instructions for developing a protein named “huntingtin”. However, the effect of the protein is still unclear. It is believed though to be involved with the brain’s nerve cells (neurons). It has been found to play an important role in normal development prior to birth.
The abnormal gene causes a malformation of the huntingtin protein resulting in clumps in various parts of the brain and eventually causing nerve cells in those areas to die.
One section of the brain that is affected is the area that coordinates movement. Another area primarily affected is the cortex which controls thought, memory, and perception.
About HD’s Symptoms
The symptoms of HD usually appear in adulthood. They are:
- reduced muscle coordination
- behavioral abnormalities
- severe emotional disturbance
- cognitive decline
- physical and mental deterioration
Ongoing Research
Scientists are attacking the disease in many different directions.
- Basic neurobiology: studying the HD gene for a more in-depth understanding of what causes the disorder.
- Imaging: PET scans and similar technologies that allow scientists to observe how the gene affects the brain’s structures and the body’s chemistry and metabolism.
- Animal models: the breeding of mice or other laboratory animals and duplicating characteristics of the disease will allow scientists to gain knowledge of its progression and its symptoms.
- Fetal tissue research: HD patients present nerve degeneration. In order to decide on optimal methods of restoration and replacement of these functions, scientists implant fetal tissue in laboratory animals.
- Genetic studies: Research involving genetic studies of the inheritance patterns of families is ongoing with the goal of understanding how HD passes through generations.
- Clinical trials: Several successful clinical trials are usually required before a drug may be considered for FDA approval. Trials of drugs to treat HD would include finding the essential genetic defect that is the cause of the condition. Various classes of drugs would be tested with the intent of controlling symptoms and slowing the progression.
The Diagnosis
The diagnosis for HD is based primarily on an oral examination by a psychiatrist and a neurologist, a physical examination, and a review of family medical history.
An Encouraging Discovery
The Drosophila fruit fly carries the HD gene defect. Scientists at the University of California, Irvine using an HDAC inhibitor have been successful in preventing cell death in the fruit fly model. This discovery gives insight into the genetic mutation’s alteration of chemical pathways that cause the disease. The HDAC inhibitor (Histone deacetylases) is currently being tested in clinical trials to treat cancer.
The scientists believe that they have now discovered a method to slow and even possibly prevent HD.
