A Huntington’s disease drug in a new formulation receives US FDA approval

Huntington’s disease is an inherited condition that causes the progressive breakdown of nerve cells in the brain, leading to a gradual decline in motor control, cognition and mental stability.

The United States Food and Drug Administration (FDA) has approved the granular formulation of a drug from American biopharmaceutical company Neurocrine Biosciences, which develops treatments for neurological and endocrine diseases and disorders.

The drug Ingrezza (valbenazine) is indicated for the treatment of movement disorders (tardive dyskinesia) associated with Huntington’s disease, the company said in a statement on Tuesday.

The drug was first approved in 2017 as an oral capsule to treat adults with movement disorders, tardive dyskinesia and chorea.

The new oral granule treatment was developed as an alternative for patients with tardive dyskinesia and chorea who experience difficulty swallowing capsules.

Valbenazine is a vesicle monoamine transporter 2 (VMAT2) inhibitor.

The company did not provide details on the drug’s availability and price.

Huntington’s disease or Huntington’s disease, named after the American doctor George Huntington, the first to scientifically describe this disease in 1872, is a progressive hereditary neurodegenerative condition in which the loss of certain neurons in the brain causes motor, cognitive and psychiatric symptoms.

The disease is characterized by dementia, cognitive decline, poor muscle coordination, and chorea – a syndrome manifested by involuntary, irregular, unpredictable movements, affecting different regions of the body (head, neck, upper limbs or lower limbs), sometimes with large amplitude of movements, affecting balance or walking.

This genetic disorder (with autosomal dominant transmission) affects the central nervous system and causes progressive degeneration of brain cells.

The condition, known in the past (1500 AD) as St. John’s or St. Vitus’ dance (the term “chorea” derives from the Greek word “choreia,” meaning “dance”), is the result of a genetic mutation that causes the abnormal expansion of the CAG repeats in DNA, which encode the amino acid glutamine.

The resulting product, a large protein called huntingtin, has an increased sequence of polyglutamine residues, which leads to the appearance of the disease, the pathophysiological mechanism being currently unknown.

Huntingtin protein selectively accumulates in brain cells sensitive to toxic levels of this protein. The caudate nucleus atrophies, the population of small cells degenerates and the level of the neurotransmitter γ-aminobutyric (GABA) and substance P decreases.

This rare form of dementia affects both sexes equally, and symptoms generally appear between the ages of 30 and 50 and worsen over a period of 10 to 25 years.

Huntington’s disease is estimated to affect about 41,000 Americans, and more than 200,000 are at risk of inheriting the disease.

Tardive dyskinesia is a movement disorder characterized by uncontrollable, abnormal and repetitive movements of the face, trunk and/or other parts of the body, which can be disruptive and have a negative impact on patients.

The condition is associated with taking certain types of mental health drugs (antipsychotics) that help control dopamine receptors in the brain,

Antipsychotics help balance emotional states and are commonly prescribed to treat mental illnesses such as major depressive disorder, bipolar disorder, schizophrenia and schizoaffective disorder and other prescription drugs (metoclopramide and prochlorperazine) used to treat gastrointestinal disorders are associated with tardive dyskinesia.

In patients with tardive dyskinesia, these treatments are thought to result in irregular dopamine signaling in a region of the brain that controls movement. Symptoms can be severe and are often persistent and irreversible.

It is estimated that tardive dyskinesia affects about 600,000 people in the United States alone.

Most people with Huntington’s disease have disease-associated chorea, an abnormal involuntary movement disorder characterized by irregular and unpredictable movements. Chorea can affect different parts of the body and interfere with motor coordination, walking, swallowing and speaking.

The recent authorization was based on positive data demonstrating the equivalence and tolerability of the granules compared to the currently approved capsule version.

The oral granules, available in three doses – 40 mg, 60 mg and 80 mg – should be sprinkled on soft food before administration.

Another drug for the treatment of tardive dyskinesia and chorea associated with Huntington’s disease, Austdedo (deutetrabenazine), from the Israeli drug company Teva Pharmaceuticals, was also approved for marketing in the United States last February.