NICE has issued draft guidance for public consultation which recommends sapropterin (≤10 mg/kg) for treating phenylketonuria (PKU) in children aged up to 18 years. The draft guidance does not recommend sapropterin for adults.
The clinical trial evidence shows that sapropterin reduces blood phenylalanine levels in people with PKU but it is uncertain how well it works because there is only short-term clinical trial evidence.
NICE acknowledged that sapropterin could prevent long-term irreversible brain damage in children, because childhood is the most critical period for brain development. However, there was uncertainty as to what extent sapropterin reduces reliance on a protein-restricted diet.
Furthermore, there were limitations with the economic analyses presented, which made it difficult to estimate the cost-effectiveness of sapropterin. NICE concluded that the cost-effective estimate for sapropterin in children is likely to be within the range considered an effective use of NHS resources.
Adults, whose neurological development is complete, are not susceptible to irreversible brain damage caused by uncontrolled phenylalanine levels in the same way as children. Adults also need a higher dose of sapropterin than children. These factors, taken together with uncertainties about the extent to which it reduces reliance on a protein-restricted diet, the absence of data on whether sapropterin might improve quality-of-life, and limitations of the cost-effectiveness analyses presented mean that sapropterin in adults was not considered to be a cost-effective use of NHS resources.
Because of a lack of evidence, NICE was unable to make a recommendation on the use of sapropterin for pregnant women and women of childbearing age.
The draft guidance is open for public consultation until 5 pm 18 March 2021. Comments can be submitted here.
