NICE draft guidance extends recommendation for sapropterin to pregnant women

NICE has issued final draft guidance recommending sapropterin (also called Kuvan and made by BioMarin) as an option to treat phenylketonuria (PKU) in pregnant women until they give birth as well as for treating the condition in people until they turn 22.

PKU is a rare, inherited, chronic and life-long metabolic condition usually diagnosed in children. It is caused by the deficiency of an enzyme that breaks down phenylalanine, a compound that occurs naturally in protein-rich foods such as milk, eggs and meat. Phenylalanine in high concentrations is toxic to the central nervous system.

The current treatment for PKU is a lifetime adherence to a severely protein-restricted diet which cuts out most natural proteins (such as meat, fish, eggs, cheese, pulses, seeds, flour, bread and pasta), together with dietary supplementation. Treatment with sapropterin aims to reduce blood phenylalanine levels and relax the protein-restricted diet as much as possible.

Following public consultation on NICE’s previous draft guidance which recommended sapropterin for children up to 18 years old, the committee agreed that PKU is a particular concern if poorly controlled during pregnancy because it can cause severe congenital defects in unborn children.

Currently, only pregnant women with PKU who aren’t able to control their condition through diet alone are able to access sapropterin on the NHS. This new recommendation could allow women to have sapropterin earlier in their pregnancy with potentially better outcomes for their unborn children.

Meindert Boysen, deputy chief executive and director of the Centre for Health Technology Assessment at NICE, said: “Although we’re pleased to now be able to recommend sapropterin for people up to 22 years of age and pregnant women, it’s disappointing not to have been able to extend the recommendation to all adults.

Even when considering some additional potential benefits of sapropterin in this group, the price of the drug was too high to allow it to be considered an acceptable use of NHS resources. The committee were aware that generic products could be available in the near future and hoped these would be priced to allow access to this drug for all adults with PKU.”