NICE recommendations about sapropterin (Kuvan).

What they mean for patients with PKU:


Who is NICE and what has the NICE committee said?

NICE is the institution which assesses the cost effectiveness of medicines for the NHS and decides whether the medicine should be routinely used by patients. NICE guidance is applied in England and Wales and is usually followed in Northern Ireland. Scotland has a separate system.

NICE has assessed sapropterin/Kuvan and said:

– Patients will be able to take Kuvan if they are under 22. They can take Kuvan until their 22nd birthday.
– Patients who are pregnant can take Kuvan from their positive pregnancy test until they give birth.
– Patients who are 22 or older will not be able to start taking Kuvan based on this current guidance. This is due to the higher average costs of treating adults with PKU. NICE has said they are aware that cheaper generic versions of Kuvan will be available soon and “hoped these would be priced to allow access to this drug for all adults with PKU”.

What is (sapropterin) Kuvan and what does it do?

Kuvan is the brand name for a medicine called sapropterin, for PKU. Sometimes sapropterin is also called BH4.
We have a full factsheet here:


My child has PKU. Will my child be able to take Kuvan?

Sapropterin/Kuvan does not work for all patients with PKU. It depends which PKU gene mutations the patient has. It is estimated about 20-30% of patients in the UK will be responsive to Kuvan treatment. Your clinic will need to find out whether your child is responsive to Kuvan treatment by “response testing” your child. This involves giving your child Kuvan and seeing if phenylalanine levels drop 30%. If your child is responsive to the medicine they will start long-term treatment. The process for testing teenagers and young adults will be the same.

How soon will it take to start Kuvan response testing?

The drugs and other treatments recommended by NICE must be funded by the NHS, by law, through what’s called the ‘funding directive’. Normally, when the funding directive is applied, the NHS has 90 days to make the treatment available in England and 60 working days in Wales. In practice this can happen much sooner.

However even if Kuvan becomes available quickly, it is unlikely that clinics will be able to response test everyone straightaway. It is important that the process is done carefully with supervision from your metabolic team. You may need to wait to allow time for the clinics to do the response testing.

Do I need to contact my clinic about access to Kuvan?

NSPKU is seeking more updates from the clinics about the arrangements that will be made and we will make further announcements. We suggest you don’t contact your clinics separately at this time as this may put a strain on clinic staffing.

I am a woman with PKU who is pregnant, planning a pregnancy or is at risk of pregnancy. What does the guidance mean for me?

NICE has not recommended Kuvan for adults except for women who are pregnant. Women will now be able to access Kuvan from a positive pregnancy test until birth.

NSPKU is very disappointed that NICE did not recommend access to women in the pre-conception stage.

If you are pregnant/planning a pregnancy we suggest you contact your metabolic team for guidance about undertaking genetic and/or response testing.

Guidance about different UK nations:

England and Wales : NICE guidance will be applied and Kuvan should become available soon.

Northern Ireland : The Department of Health, Social Services and Public Safety (DHSSPS) in Northern Ireland agreed to link to NICE. This means that they look at any guidance issued by NICE and decide if it is relevant for Northern Ireland. The DHSSPS usually approves most NICE guidance.

Scotland : Scotland has a separate body which assesses drugs and does not recognise NICE guidance.

I am an adult with PKU. Will access to Kuvan or sapropterin ever be widened to include me?

The NICE guidance did not recommend access to adults over the age of 22 because of the extra average costs of treating adults with PKU. However the guidance leaves open the possibility that unbranded, or “generic” versions of sapropterin may allow access to all patients with PKU. NSPKU is in communication with the NHS and NICE about this issue and we remain committed to seeking full access for all people with PKU.

NSPKU remains committed to seeking access to Kuvan for all patients with PKU in all parts of the UK. We are aware that Kuvan will not work for all people with PKU and our aim is to obtain access to any licensed and effective treatments for PKU that can help people live healthy lives. PKU is a lifelong condition and NSPKU campaigns for treatment and support for patients at all stages of their life.

Friday 20th August 2021