This is misleading at best. The NHS Comissioning Board has commissioned Sapropterin for use. However, due to its extraordinarily high costs and limited efficacy compared to maintaining a restricted diet, it is only prescribed in scenarios where there is an urgent clinical need for treatments like Sapropterin.

The NHS Commissioning Board's report on Tetrahydrobiopterin/Sapropterin/Kuvan is here: https://www.england.nhs.uk/wp-content/uploads/2013/04/e12-p-...