Overall, patients who received tetrabenazin, which is currently being reviewed by the FDA, were six times as likely to be considered by their doctors to have improved considerably, compared to participants who received a placebo.
If approved, the medication would be the first authorized by the FDA expressly for the treatment of Huntington’s disease, which affects about 30,000 people in the US.
Huntington’s disease is an inherited brain disorder that causes patients to experience uncontrollable jerky movements (chorea), as well as changes in personality, behavior, thinking and memory. There are no FDA-approved treatments for the chorea.
Tetrabenazine was originally developed in the 1950s to treat psychosis, but was quickly pushed aside by more effective medications. But doctors in the UK found it to be effective to treat the excessive involuntary movements of Huntington’s, and it is approved for use in several nations. In the US, tetrabenazine is designated as an “orphan drug” by the FDA since it’s targeted to a disease directly affecting fewer than 200,000 people in the nation.
The symptom that tetrabenazine treats – involuntary, writhing movements of the limbs, face, and sometimes the entire body – is the hallmark symptom of Huntington’s disease, an inherited neurodegenerative disorder that worsens as brain cells known as medium spiny neurons are killed off by a mutant protein.
The study was conducted by the Huntington Study Group and was funded by Prestwick Pharmaceuticals of Washington, DC, the company that owns the rights to develop and sell the medication in the US.