No approved therapies exist to target the underlying cause of Huntington’s, a disease caused by a mutation in the huntingtin gene . This mutation leads to the formation of a protein that misfolds and aggregates inside nerve cells, killing them.
AMT-130, the newly approved therapy, stops production of the mutated form of the huntingtin protein. The investigational drug consists of a small portion of synthetic genetic material, called microRNA (miRNA), which binds to the messenger molecule carrying the genetic information needed to make the huntingtin protein, marking it for elimination.
In April 2017, uniQure published the results of a preclinical study of AMT-130, showing that its drug was able to penetrate the brain and spinal cord following direct injection in a primate.
Moreover, the injections delivered the treatment with precision and no side effects, researchers reported. AMT-130’s delivery component is an adeno-associated viral vector serotype 5 (AAV5).
The study, “MR-guided parenchymal delivery of adeno-associated viral vector serotype 5 in nonhuman primate brain,” appeared in the journal Gene Therapy.
The FDA based its regulatory decision on these and other, earlier studies on AMT-130. An orphan drug designation provides a special status for investigational therapies developed for rare diseases, classified as those affecting no more than 200,000 Americans.
“Attaining orphan designation recognizes the potential that AMT-130 holds in delivering meaningful therapeutic benefit to patients suffering from this devastating disease,” Matthew Kapusta, CEO of uniQure, said in a press release. “It supports our ongoing development in Huntington’s as we seek to bring the first gene therapy approach to this disease into the clinic next year.”
The orphan drug program offers U.S. market exclusivity for up to seven years. If the European Medicines Agency grants AMT-130 similar status, the drug will have up to ten years of exclusivity in the member states of the European Union. The designation also confers tax and financial incentives for companies developing therapeutic products for rare diseases.