Raptor Pharmaceuticals Corp. announced that the US Food and Drug Administration (FDA) has granted orphan drug designation for cysteamine bitartrate (cysteamine) for the treatment of Huntington's disease (HD).

Cysteamine is currently approved by the FDA and European Medicines Agency (EMEA) to treat nephropathic cystinosis (cystinosis), a rare lysosomal storage disease. Preclinical results suggest that cysteamine has neuroprotective effects that could potentially help treat HD. Raptor's clinical development subsidiary, Bennu Pharmaceuticals Inc. (Bennu), plans to evaluate cysteamine in patients with HD.

HD is a rare and hereditary neurological disease thought to occur in approximately 1 out of every 20,000 people resulting in around 20,000 patients in the US presently. There is currently no drug available that targets the unique molecular defect that is believed to cause HD, a progressive disease that often leads to death within 15 to 20 years after diagnosis. HD is caused by a defective gene resulting in the degeneration of certain nerve cells in the brain. The disease is characterized by uncontrollable movements and mood swings or depression, followed by dementia. Preclinical findings on cysteamine's mechanism of action suggest that it has neuroprotective effects by increasing the levels of BDNF, a neuroprotective neurotrophic factor, in the brain of HD mice. BDNF levels may also be a potential biomarker of efficacy for cysteamine in HD, an important development issue when a therapy is used to prevent or slow clinical manifestation of a disorder.

The 1983 Orphan Drug Act provides important economic incentives to encourage companies to develop potential therapies for the diagnosis, prevention and/or treatment of rare, serious diseases affecting 200,000 persons or less in the US. Orphan drug designation by the FDA allows for seven years of market exclusivity following approval of a New Drug Application, as well as reduced regulatory fees and additional regulatory support for research and development initiatives.

Ted Daley, president of Bennu, stated, "Huntington's Disease is a terrible, debilitating disorder with no current cure. Available drugs can only minimize symptoms, such as uncontrollable movements and mood swings. The FDA's decision to grant cysteamine orphan drug designation in Huntington's disease complements our efforts to develop additional indications for cysteamine. We will be building off of the existing preclinical data that shows cysteamine's safety and potential efficacy to treat HD. We look forward to initiating a phase II clinical study in HD patients in 2008."

Dr. Christopher M. Starr, Raptor's chief executive officer, stated, "We are delighted that the FDA has granted orphan drug designation for cysteamine in HD. Our team at Raptor is well-versed in developing and gaining regulatory approval of new therapies for orphan drug disorders. We hope to contribute some of this orphan drug expertise and know-how to facilitate Bennu's clinical program for HD".

Through its acquisition by merger of Encode Pharmaceuticals in December 2007, Bennu obtained an exclusive, worldwide license to the intellectual property rights for the development of cysteamine from UC San Diego for the treatment of certain diseases including cystinosis, non-alcoholic steatohepatitis (NASH) and Huntington's disease.

Raptor Pharmaceuticals Corp.'s business consists of two segments: its 100% ownership of development stage biotechnology company Raptor Pharmaceutical Inc. (Raptor Inc.); and its 100% ownership of clinical-stage development company Bennu. Raptor Inc. bioengineers novel drug candidates and drug-targeting platforms derived from the human receptor-associated protein (RAP) and related proteins, while Bennu advances clinical-stage product candidates towards marketing approval and commercialization.