Multi-disciplinary implementation of sapropterin for treatment of phenylketonuria patients in a Regional Metabolic Centre

Abstract

Phenylketonuria (PKU) is a rare, autosomal recessive metabolic disorder caused by deficiency of phenylalanine hydroxylase affecting about 1/10,000 babies born in the UK, requiring lifelong treatment with an ultra-low protein diet to restrict phenylalanine intake. Sapropterin is an analogue of tetrahydrobiopterin, a PAH co-factor, indicated for the treatment of responsive patients of all ages with PKU, defined as a reduction of 30% or more in phenylalanine blood concentration.

A pharmacist-dietitian multidisciplinary team led the Implementation of high-cost drug Sapropterin for PKU patients at Queen Elizabeth Hospital Birmingham. Sapropterin was recommended by NICE TA729, NHSE commissioning position and BIMDG consensus pathway for commencing sapropterin.

From December 2021 to November 2023, 21 out of 35 patients with at least one PAH amenable variant responded after testing, with an average phenylalanine blood concentration reduction of 49% and a mean increase in natural protein intake of 126%.

Multi-disciplinary management optimise Sapropterin prescription and increase natural protein intake. The service has expanded its capacity by developing the role of specialist dietitian supplementary prescriber. Use of pharmacogenomic data allowed personalised care for patients with Sapropterin amenable variants, improving their lives by allowing some a normal diet for the first time in their lives.