CHARLOTTE, N.C. – The Food and Drug Administration has granted orphan drug status for a treatment targeting a neurogenic disorder licensed by Chelsea Therapeutics.

Chelsea plans to launch a Phase III clinical trial later this year for Droxidopa, which has been used in Japan since 1989. The drug treats symptomatic neurogenic orthostatic hypotension, or NOH, in patients with primary autonomic failure. NOH is associated with such diseases as Parkinson’s.

NOH limits release of a neurotransmitter called norepinephrine, which signals blood vessels and the heart. The result is dizziness and blurred vision caused by decreased blood pressure when a person stands. Droxidopa increases the supply of norepinephrine.

Some 300,000 people in the U.S. and Europe suffer from NOH, according to estimates by Chelsea. The company is also seeking approval for the drug in Europe. Droxidopa produces annual revenues of $50 million in Japan.

Orphan drug status is for drugs that treat diseases affecting fewer than 200,000 people in the U.S. Benefits include tax credits linked to clinical trial expenses and FDA assistance in clinical trial design. The FDA also grants seven years of exclusivity for drugs once approved. The orphan drug program is used to encourage dement of drugs targeting smaller numbers of people.

If Chelsea receives orphan drug status for Droxidopa in Europe, it would receive 10 years of market exclusivity.

“Receiving this designation is an important step in both our clinical development and planned commercialization of Droxidopa, providing Chelsea with considerable strategic advantages by providing market exclusivity, reducing clinical development costs and facilitating future regulatory filings," said Simon Pedder, Chelsea’s chief executive officer.

 "With seven years of exclusivity in place in the U.S. and 10 years in the [European Union’, either under orphan designation or as a new chemical entity, we have secured the necessary exclusivity to move aggressively ahead in our planned development of Droxidopa,” he added.