GCC Pompe Disease Patient Flow Model

Pompe disease in the GCC is a consanguinity-elevated lysosomal storage disorder, with incidence estimated at 1 in 20,000 to 30,000 live births versus roughly 1 in 40,000 globally. Saudi Arabia added Pompe disease to its national newborn-screening panel in 2021, producing an expected 25 to 35 combined GCC infantile-onset detections annually, and the KFSH&RC metabolic genetics programme has treated approximately 120 Pompe patients of all subtypes over 15 years, the region's largest single-centre experience. Late-onset Pompe disease (LOPD) follows a slower path: GCC patients typically present at age 20 to 40, with baseline forced vital capacity already down to 55 to 65% predicted by the time enzyme replacement therapy begins, evidence of a diagnostic delay that runs through rheumatology and neurology before Pompe is confirmed. Total GCC prevalence is estimated at 400 to 600 patients, of whom 200 to 300 are currently on enzyme replacement therapy, the funnel's clearest treated-population anchor point.

Within that treated cohort, 40 to 60 patients, roughly one in five to one in seven of those on enzyme replacement therapy, are inadequate responders: forced vital capacity declining despite alglucosidase and already on home non-invasive ventilation. That segment is the sharpest near-term commercial target for a next-generation ERT, ahead of the broader NPHC step-edit population. A narrower figure of 80 to 120 patients appears in separate GCC payer and competitive intelligence; it tracks the region's long-term-stable, formulary-confirmed enzyme replacement cohort rather than the full 200 to 300 on-treatment estimate used here. The two figures describe overlapping but distinct populations, not competing totals, and this model uses the broader 200 to 300 on-ERT estimate as its funnel anchor.

Every AXLRx patient flow model is built on a five-layer funnel: population, disease burden (E1), diagnosis and capture (E2), treatment and eligibility (E3), market access (E4), then Year 1-3-5 projections across three scenarios. Delivered as a live Excel workbook, not a static table: 8 sheets, formulas throughout, zero hardcoded cells.

GCC Pompe disease sources: Al-Hassnan ZN et al. Clin Genet 2012, the Saudi newborn-screening programme 2022, KFSH&RC Pompe case series and home NIV programme data, the GCC metabolic and respiratory disease network registries, and NPHC Pompe programme guidelines 2023. The narrower 80-120 long-term-stable formulary figure and the broader 200-300 on-ERT estimate are reconciled in this model as overlapping populations, not competing totals.