Ionis Pharmaceuticals, formerly Isis Pharmaceuticals, announced that the U.S. Food and Drug Administration has granted Orphan Drug Designation to IONIS-HTTRx for the treatment of patients with Huntington’s disease.

“Huntington’s disease is a rare genetic neurological disease in which patients experience detrioration of both mental abilities and physical control,” said Frank Bennett, senior vice president of research at Ionis, in a statement. “Although the toxic protein produced from the huntingtin gene in (Huntington’s) patients has been a target of interest for many years, IONIS-HTTRx is the first therapy to enter clinical trial development that is designed to treat the underlying cause of this fatal disease.”

The Orphan Drug Designation entitles the company to seven years of market exclusivity in the U.S. if the drug candidate reaches the market. The designation is part of the Orphan Drug Act, which provides economic incentives to encourage the development of drugs for diseases affecting fewer than 200,000 people in the U.S. Extra incentives under the program include tax credits related to clinical trial expenses, and FDA assistance in clinical trial design.