UK Fabry Disease HTA Strategy Model

UK Fabry disease is commissioned through three different NICE and NHS routes at once, and that is the fact any HTA strategy for a new agent has to confront first. The two enzyme replacement therapies, agalsidase alfa (Replagal) and agalsidase beta (Fabrazyme), have never been through a formal NICE technology appraisal; NHS England commissions them as a highly specialised service through clinical commissioning policy, a route that predates today's Highly Specialised Technologies pathway, at an estimated £150,000 to £250,000 per patient per year post-PAS across roughly 600 UK ERT patients. Migalastat (Galafold) followed the Highly Specialised Technologies route, recommended under NICE HST4 in 2016 as the first oral, mutation-specific rare disease therapy NICE recommended, on an indirect comparison against ERT rather than a head-to-head trial, at an estimated £80,000 to £120,000 per year for around 200 UK patients. Pegunigalsidase alfa (Elfabrio) took the standard technology appraisal route, recommended under TA915 in 2023 on a subgroup argument in anti-drug-antibody-positive suboptimal responders rather than a broad-population case. One indication, three commissioning mechanisms, and no single reusable precedent for a new entrant to inherit.

The strategic consequence is that a new agent cannot copy a single Fabry precedent; it has to choose which route its evidence can actually win, and defend a different comparator for each. An oral or mutation-specific agent points at the HST4 precedent and the amenable-mutation population, where migalastat already sits and where the NHS still has not captured the switch saving at scale: moving an amenable-mutation patient from ERT to migalastat saves an estimated £70,000 to £130,000 per patient per year, a saving NICE's own HST4 analysis quantified but uptake has not realised even at the UK's world-leading migalastat penetration. A new ERT or subgroup agent instead points at TA915, where pegunigalsidase alfa won on demonstrated subgroup-specific superiority in the ADA-positive segment against an agalsidase beta comparator that was itself never NICE-appraised. Each route carries a different comparator, a different evidence bar, and a different price ceiling, and choosing the wrong one is the most expensive mistake a Fabry submission can make. Our route selection matrix scores all three against the agent's actual evidence before a dossier is drafted.

Every AXLRx HTA strategy model is built from primary HTA-body sources: NICE final guidance and NHS England commissioning policy documents, not secondary summaries. Every route assignment and comparator claim is pressure-tested through the 3-test defence framework before it is accepted.

UK Fabry disease HTA sources: NHS England clinical commissioning policy for agalsidase alfa and agalsidase beta, NICE HST4 final guidance for migalastat (2016), and NICE TA915 final guidance for pegunigalsidase alfa (2023), with NHS England lysosomal storage disorder commissioning budget analysis 2023.