Arena Pharmaceuticals announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug designation to APD811 for the treatment of pulmonary arterial hypertension (PAH). APD811 is an orally available agonist of the prostacyclin (IP) receptor.

Arena plans on initiating a Phase 2 clinical program for APD811 later this year based on the Orphan Drug designation. It is currently being developed for the treatment of vasospastic diseases, such as pulmonary arterial hypertension.

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Treatment with IP agonists, which can slow disease progression and improve exercise tolerance in PAH patients, is considered standard of care for advanced pulmonary arterial hypertension. Currently available IP agonists belong to the prostanoid class of molecules, and these products need to be administered frequently or continuously through intravenous, subcutaneous or inhaled delivery methods.

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