Merck Submits European Application for Sapropterin

Merck Serono has submitted an application to the European Medicines Agency (EMEA) for the marketing authorization of sapropterin as an oral treatment for significant hyperphenylalaninemia (HPA) due to phenylketonuria (PKU) or tetrahydrobiopterin (BH4) deficiency.

Sapropterin had previously received Orphan Medicinal Product designation for the treatment of HPA from both the EMEA and the FDA, Merck KGaA said.

PKU and BH4 deficiency are caused by genetic defects in the metabolism of the amino acid phenylalanine, resulting in hyperphenylalaninemia, abnormally high levels of phenylalanine in the blood. Hyperphenylalaninemia can cause serious brain damage in infants and young children and neurological impairment in older patients. There is no approved drug for the treatment of this condition in Europe.

Sapropterin is being developed in partnership with BioMarin Pharmaceutical. Under the terms of the agreement with BioMarin, Merck Serono has exclusive rights to market sapropterin in all territories outside the U.S. and Japan, and BioMarin has exclusive rights to market sapropterin in the U.S.