Swiss pharma company APR Applied Pharma Research s.a. disclosed on Thursday the receipt of the US Food and Drug Administration's (FDA) orphan drug designation for its drug candidate APR-OD031 for the treatment of Phenylketonuria (PKU).

PKU is an inherited, recessive, metabolic disorder caused by a deficiency of the enzyme phenylalanine hydroxylase (PAH) required for the breakdown of Phenylalanine (Phe), causing it to accumulate to high levels in the blood and consequently into the brain with serious neurological complications.

APR-OD031 is an extended release amino acid mix engineered with a patented drug delivery technology to enable physiological absorption of the delivered amino acids. This is the first mix of amino acids having a pharmacological primary mode of action designed to reduce and control Phe fluctuations and muscle proteolysis by reducing catabolic episodes in PKU patients, especially those not responding to Sapropterin, the company said.

APR-OD031 is engineered using the patented drug delivery Physiomimic Technology enabling the production of small coated granules for oral administration, processed to gradually release the amino acids in the gut. APR-OD031 is intended to reduce Phenylalanine fluctuations and muscle proteolysis in PKU patients not responding to Sapropterin.