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Addition to medicines database - Kuvan for phenylketonuria

Kuvan, for Phenylketonuria from BioMarin

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We have updated the medicine containing the ingredient sapropterin, brand name Kuvan.

Kuvan is a medicine that is used to treat high blood levels of phenylalanine in adults and children of all ages with the genetic disorders phenylketonuria (PKU) or tetrahydrobiopterin (BH4) deficiency.

Patients with these disorders cannot process the amino acid phenylalanine from dietary protein, and as a result the amino acid builds up in the blood to abnormally high levels, causing problems in the nervous system.

Because the number of patients with conditions leading to high phenylalanine levels is low, the conditions are considered ‘rare’, and Kuvan was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 8 June 2004.

Kuvan contains the active substance sapropterin dihydrochloride.

Because the number of patients with conditions leading to high phenylalanine levels is low, the conditions are considered ‘rare’, and Kuvan was designated an ‘orphan medicine’ (a medicine used in rare diseases) on 8 June 2004.

This medicine can only be obtained with a prescription.

For more information see full article.

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About phenylketonuria (source NHS)
Phenylketonuria (PKU) is a rare but potentially serious inherited disorder.

Our bodies break down protein in foods like meat and fish into amino acids, which are the "building blocks" of protein.

These amino acids are then used to make our own proteins. Any amino acids that aren't needed are broken down further and removed from the body.

People with PKU can't break down the amino acid phenylalanine, which then builds up in the blood and brain. This can lead to brain damage.

How Kuvan works (source EMA)
The high levels of phenylalanine in the blood are due to a problem with the breakdown of phenylalanine through the enzyme ‘phenylalanine hydroxylase’. Patients with PKU have defective versions of the enzyme, and patients with BH4 deficiency have low levels of BH4, a ‘cofactor’ that this enzyme needs to work properly.

The active substance in Kuvan, sapropterin dihydrochloride, is a synthetic copy of BH4. In PKU, it works by enhancing the activity of the defective enzyme, while in BH4 deficiency it replaces the missing cofactor. These actions help restore the ability of the enzyme to convert phenylalanine into tyrosine, thereby reducing phenylalanine levels in the blood.

Kuvan was first made available in the EU in 2008. It is manufactured by BioMarin.

European Medicines Agency website page for Kuvan
NHS website for phenylketonuria
Contains public sector information licensed under the Open Government Licence v3.0.
Accessed 21/03/19
Links available in full article

EMA information on Kuvan

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