Droxidopa demonstrates benefit in Ph IIb NOH trial

North Carolina, USA-based biopharmaceutical company Chelsea Therapeutics says that the results of a Phase IIb trial of its hypotension treatment droxidopa, a synthetic amino acid, indicate that it brought about a statistically-significant reduction in the fall in orthostatic systolic blood pressure. The drug, which was licensed from Japan's Dainippon Sumitomo Pharma (Marketletter June 5, 2006), is being developed as a therapy for neurogenic orthostatic hypotension in patients with multiple system atrophy and Parkinson's disease.

NOH is a disorder caused by insufficient release of the neurotransmitter norepinephrine, which is used by the sympathetic autonomic nerves to send signals to the blood vessels of the heart. The deficiency results in decreased blood pressure when a person assumes a standing position, and is characterised by dizziness, blurred vision and syncope.

During the trial, which was a double-blind, placebo-controlled, parallel group assessment, 125 patients received one of three doses of the drug (100mg, 200mg or 300mg) three times a day, or placebo. The results showed that treatment with 300mg reduced the fall in orthostatic blood pressure, compared with the other groups. In addition, the firm reported that the use of dopamine decarboxylase inhibitors did not limit the agent's therapeutic effect.