UK Pompe Disease Payer & HTA

Alglucosidase alfa (Lumizyme/Myozyme) has been commissioned by NHS England as a highly specialised service since 2014, under an NHS clinical commissioning policy rather than a formal NICE technology appraisal, with a confidential Patient Access Scheme bringing net cost to an estimated £200,000-£350,000 per patient per year for the roughly 180 UK patients currently on enzyme replacement therapy. The NHS commissioning policy's continuation criteria require FVC and 6-minute walk test (6MWT) reassessment at 12 and 24 months; therapy is discontinued if FVC declines by 20% or more alongside a 10% or greater 6MWT decline over 12 months, confirming clinical benefit is no longer demonstrated. UK Pompe Consortium outcomes registry data show approximately 25% of UK late-onset Pompe disease (LOPD) patients on alglucosidase experience FVC decline of 5-15% over five years, inadequate responders by the commissioning policy's own criteria, and the roughly 45-50 patients this represents are the defined switch-eligible population for next-generation therapy.

Avalglucosidase alfa (Nexviazyme) has since been recommended by NICE under TA821, with a confidential commercial arrangement, following an appraisal in which Sanofi presented two evidence scenarios: a switch indication for alglucosidase inadequate responders, and a first-line indication for treatment-naive LOPD patients. The COMET trial showed a 23.5-metre 6MWT improvement and preserved FVC against a 13.2-metre 6MWT decline for alglucosidase, a meaningful functional advantage. Avalglucosidase's WAC carries an estimated 20-30% premium over alglucosidase, so the NHS budget impact still depends on real-world uptake by population: for the 45-50-patient switch population, the incremental NHS budget impact is a manageable £2-4M per year; broader first-line uptake across all new LOPD patients would create a materially larger budget differential.

This assessment is built from NHS England Pompe commissioning policy documentation, NICE technology appraisal TA821 (avalglucosidase alfa), the COMET trial evidence base, and UK Pompe Consortium outcomes registry data.

Key sources: NHS England Pompe commissioning policy documentation (2014); NICE technology appraisal TA821 (avalglucosidase alfa, final guidance) and COMET trial design (Sanofi UK submission, 2023); UK Pompe Consortium outcomes registry 2023; NHS England Pompe commissioning budget analysis.