Amarantus BioScience Holdings, a San Francisco-based biotechnology company focused on developing products for Regenerative Medicine, Neurology and Orphan Diseases, announced that it has received orphan drug designation from the U.S. FDA for Eltoprazine in the treatment of Parkinson’s disease levodopa-induced dyskinesia (PD-LID).  Parkinson’s disease is a chronic, progressive motor disorder that causes tremors, rigidity, slowed movements and postural instability. The Parkinson’s Disease Foundation estimates that there were approximately one million people living with Parkinson’s disease in the United States in 2011.  The most commonly-prescribed treatments for Parkinson’s disease are levodopa-based therapies.  In the body, levodopa is converted to dopamine to replace the dopamine loss caused by the disease.  The therapeutic efficacy of levodopa is gradually lost over time, and abnormal involuntary movements, dyskinesias, gradually emerge as a prominent side-effect in response to previously beneficial doses of the drug.