Chelsea Therapeutics International, Ltd, a biopharmaceutical development company, has entered into an exclusive license agreement with Dainippon Sumitomo Pharma Co., Ltd. for the global development and commercialization rights to L-Threo DOPS (L-DOPS or Droxidopa), excluding Japan, Korea, China and Taiwan.

Droxidopa, a synthetic amino acid for the treatment of neurogenic orthostatic hypotension, currently generates annual revenue of approximately $50 million in Japan.

On May 8, Chelsea announced its intent to seek Orphan Drug Status and begin clinical development of Droxidopa for the treatment of neurogenic orthostatic hypotension. In securing development rights from DSP, Chelsea gains access to all clinical data and manufacturing processes related to Droxidopa's 20-year combined clinical and commercial development by DSP. This data is expected to reduce the required clinical testing for US and EU marketing approval and expedite critical path to commercialization. Chelsea anticipates filing its application for Orphan Drug Status with the US FDA and European Health Agencies in the third quarter of 2006 and subsequently initiating a clinical program for Droxidopa in 2007.

"This licensing agreement with DSP provides Chelsea with exclusive access to a substantial body of clinical safety and efficacy data believed to be applicable to both the US and EU regulatory approval process -- further supporting an expedited development program and creating a sizable barrier to entry for potential competitors," commented Dr. Simon Pedder, Chelsea's president and chief executive officer. "Assets and advantages provided by this agreement, combined with our planned orphan drug strategy and Life Cycle strategy, uniquely position Chelsea to realize the global potential of Droxidopa and capture an attractive commercial market."

Droxidopa is currently marketed in Japan by DSP, the fifth-largest pharmaceutical company in Japan and among the top 40 pharmaceutical companies worldwide.

The compound initially received approval in 1989 for the treatment of frozen gait or dizziness associated with Parkinson's disease and for the treatment of orthostatic hypotension, syncope or dizziness associated with Shy-Drager syndrome and Familial Amyloidotic Polyneuropathy. In 2000, DSP received expanded marketing approval to include treatment of vertigo, dizziness and weakness associated with orthostatic hypotension in haemodialysis patients.

Chronic, symptomatic orthostatic hypotension is a neurogenic disorder resulting from a deficient release of norepinephrine, the neurotransmitter used by autonomic nerves to send signals to the blood vessels and the heart. This deficiency results in sudden, decreased blood pressure when a person assumes a standing position and is characterized by light-headedness, dizziness, blurred vision and syncope. Droxidopa, an orally active synthetic precursor of norepinephrine, increases the supply of norepinephrine available for delivery to its receptors to improve orthostatic blood pressure and alleviate symptoms of orthostatic hypotension.

An estimated 100,000 US patients suffer from chronic, symptomatic orthostatic hypotension which is commonly associated with Parkinson's disease, Pure Autonomic Failure (PAF) and Multiple System Atrophy (MSA), a name that encompasses disorders previously known as striatonigral degeneration, olivoponto-cerebellar atrophy and the Shy-Drager syndrome.