Merck Serono launches Kuvan in Europe

Kuvan, the first treatment for two rare neurological disorders, has been launched in the UK, France and Germany.

Merck Serono's drug is indicated for patients with hyperphenylalaninaemia (HPA) due to phenylketonuria (PKU) or tetrahydrobiopterin (BH4) deficiency.

Kuvan has been available in the US since 2007and will be rolled out in another ten European countries this year.

The inherited conditions, which affect 35,000 people in the EU, are diagnosed at birth and characterised by abnormally high levels of phenylalanine in the blood.

If left untreated they can lead to brain damage in infants and children, and neurocognitive impairment in teenagers and adults.

Authorities recommend that therapy should begin as early as possible.

"This treatment may contribute to prevent the appearance of potential transient to non-reversible mental impairment," explained Roberto Gradnik, executive vice president commercial Europe at Merck Serono.

Diet has previously been the main means of controlling phenylalanine levels, cutting out high-protein foods such as meat, eggs and dairy.

Merck Serono said the drug could reduce the need to limit phenylalanine intake.

In phase III trials of patients with HPA due to PKU, it lowered blood phenylalanine levels and increased dietary phenylalanine tolerance.

Gradnik said US health professionals have given the drugs "positive testimonials", as have patients whose quality of life has improved with treatment.

However, only up to half of PKU patients respond to Kuvan.

HPA due to PKU deficiency is the most prevalent of the two diseases, with BH4 deficiency accounting for just 1-2% of HPA cases.

The marketing authorisation for Kuvan soluble tablets was granted by the European Commission in December last year.

It applies to the 27 countries of the EU as well as Iceland, Liechtenstein and Norway.

"As part of our commitment to patients, Merck Serono will continue to investigate innovative treatment options for patients with high unmet medical needs," Gradnik concluded.

The company is developing Kuvan in partnership with California-based biopharma firm BioMarin Pharmaceutical.

Merck Serono owns exclusive rights to market Kuvan outside North America (where BioMarin will market it) and Japan (where it will be marketed by Daiichi Sankyo).