Huntington's Disease

Avicena is presently developing HD-02, a novel drug candidate for the treatment of HD which has been granted orphan drug designation by the United States Food and Drug Administration (FDA). The company has recently completed a Phase II clinical study of HD-02 at Massachusetts General Hospital. Results from this study, which were published in the journal Neurology, showed HD-02 to be safe and well-tolerated. In addition, findings showed an increase in serum and brain creatine levels and a reduction in an oxidative marker in the treatment group.

In preclinical studies performed by Dr. Flint Beal of Cornell Medical Center, this compound has shown significant neuroprotective effects such as improved motor movement and increased survival rate.

What is Huntington's Disease
HD is a progressive neurodegenerative disease caused by a defective gene that is often inherited from parent to child. This genetic defect causes a programmed deterioration of neurons in those parts of the brain that are responsible for controlling cognitive, emotional and motor functions. This progressive deterioration results in a variety of symptoms including uncontrolled muscle movement, loss of intellectual capacity, and severe emotional disturbances.

While early signs of the disease vary greatly from individual to individual, a common observation is that the earlier the symptoms appear, the more rapidly the disease progresses.

back to top

Types of Huntington's Disease
There are two main classifications of HD: "familial" and "sporadic." Familial HD, which accounts for a majority of HD cases, results from the inheritance of the genetic defect from parent to child. In cases of sporadic HD, the genetic defect responsible for the disease is the result of a genetic mutation and not inheritance.

back to top

Symptoms of Huntington's
Typically, symptoms of HD begin to manifest themselves between the ages of 30 and 50, though they can begin to appear much earlier or later. Also important to note is the fact that symptoms can range dramatically from patient to patient, even within the same family.

Early symptoms of HD include slight, uncontrolled muscle movement, clumsiness, lack of concentration, short term memory loss, mood swings, and depression. As the disease progresses, patients may begin to experience involuntary muscle movement, weight loss, and difficulty with speech and swallowing. At the same time, individuals will often experience deterioration of intellectual capacity, as well as severe emotional disturbances.

back to top

Progression of Huntington's Disease
Progression of HD typically occurs over the course of 10 to 30 years and is marked by increasing deterioration of motor movement, memory capacity and emotional well-being.

Typically, the first signs of the disease are involuntary muscle twitching and reduced muscle coordination, as well as depression, mood swings and increased forgetfulness. In later stages of HD, patients will exhibit a lack of concentration, as well as severely diminished short-term memory. Additionally, involuntary movement of the head, arms, legs and trunk will increase.

Eventually, walking, speaking and swallowing will become increasingly difficult. At the same time, judgment and memory will be severely impaired. In the final stage of HD, patients are often unable to care for themselves.

back to top

Diagnosis of Huntington's Disease
While genetic testing can be used to determine if an individual has the HD gene, it will not be able to determine the point at which a person will begin to show symptoms of the disease. That being said, an individual who has been identified as carrying the defective gene will eventually develop HD.

back to top

Causes of Huntington's Disease
HD is the direct result of a genetic defect that causes a programmed deterioration of neurons in those parts of the brain that are responsible for controlling cognitive, emotional and motor functions. While the vast majority of HD cases are caused by inheritance of the defective gene, some cases are the result of a new genetic mutation unrelated to inheritance.

back to top

Incidences of Huntington's Disease
Currently in the United States, there are approximately 35,000 individuals affected by HD. Furthermore, it is estimated that about 175,000 people have a genetic risk for developing the disease.

The disease typically strikes individuals between the ages of 30 and 45, although juvenile HD may occur as early as two years of age. HD effects male and females equally and occurs across all ethnic and racial groups.

back to top

Treatment of Huntington's Disease
While there is no known cure for HD, certain medications have been shown to ease the symptoms associated with the disease. However, it is important to note that while medication may help control the clinical symptoms, there is no treatment to stop or reverse the course of the disease. Certain treatments, such as physical and speech therapies, may also ease the progression of the disease. Additionally, proper nutrition and hydration have been shown to ease the symptoms of HD.

Avicena is presently developing a novel drug candidate for the treatment of HD. HD-02, granted orphan drug designation by the FDA, recently completed a Phase II trial led by Dr. Steve Hersch of Massachusetts General Hospital. Results from this trial, published in Neurology, showed a reduction in an oxidative marker, which some researchers have linked to reduced oxidative injury in patients with Huntington's disease. Findings also showed HD-02 to be safe and well-tolerated. Near term, Avicena intends to initiate a Phase III trial following completion of a chronic toxicology study currently underway.

back to top