Vybion Wins Orphan Drug Designation for Experimental Huntington’s Drug

According to an article published on BioPortfolio, earlier this week, biotechnology company Vybion Incorporated secured orphan drug designation for its highly experimental Huntington’s disease drug INT41.

About Huntington’s Disease

Huntington’s disease (HD), sometimes called Huntington’s chorea, is a rare, genetically inherited disease that causes the nerve cells of the brain to progressively degenerate. After visible symptoms present, Huntington’s patients typically have a life expectancy of somewhere between 15 and 20 years.

The disease itself is highly rare, affecting only between .003% and .007% of people with European ancestry. The disease is less common but still extant in other populations, such as in African, Chinese, and Japanese populations.

Due to the neurologically degenerative nature of the disease, the physical and cognitive affects are often severe. Physical symptoms include involuntary physical twitching that worsens with the progression of the disease. Eventually, some will have difficulty with breathing, or swallowing. Over time, patients develop a decline in their reasoning and thinking abilities – often, changes in personality are also detectable.

Huntington’s is usually inherited from one of the parents. The disease is expressed as on an autosomal dominant gene, meaning that only one parent needs to pass on a copy of the faulty gene for the child to later develop HD. However, some, even rarer individuals will develop Huntington’s without having it passed from a parent.

About INT41

INT41 is an intrabody, which is an antibody in your cells that acts on certain proteins. INT41 is delivered by a modified adenoassociated virus (AAV), which is a in itself not known to cause any disease. Viruses are capable of penetrating cells with great efficiency, and ironically provide the safest method of introduction. The drug received orphan drug designation on Monday the 3rd.

Orphan drug designation is granted by the FDA to medications that would treat only a small handful of Americans (fewer than 200,000), and are proceeding towards or running clinical trials. Designation comes with a litany of benefits not limited to tax credits, additional trial funding, and seven years of market exclusivity over similar drugs designed to treat Huntington’s (pending final approval). Some companies exist solely to develop these risky but potentially highly valuable drugs.

If INT41’s name wasn’t enough of a hint, the new orphan drug designation does not at all mean that Vybion’s drug is ready for market.

Only animal and method of action (showing chemically how the drug is expected to work in the body) studies have been conducted for INT41 so far. Further studies need to be conducted before INT41 receives its Investigational New Drug (IND) filing, which would allow for human testing. But Vybion doesn’t expect to file an IND for INT41 until 2020 at earliest.

That means a public rollout is probably still another four or five years away at earliest – assuming it gains approval at all.


Orphan drug designations bring lots of benefits to pharmaceutical companies. Do you think it is a good practice to grant designations so early in the life of an experimental drug? Why or why not? Share your side with Patient Worthy!

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