GCC ATTR Amyloidosis Market Sizing Model

The broad-burden method sizes GCC ATTR-CM from HFpEF and hypertrophic cardiomyopathy misattribution literature: since most heart failure with preserved ejection fraction in the region is attributed to background hypertension and diabetes without ATTR-specific workup, extrapolating from Western misattribution rates implies a total ATTR-CM burden of 15,000-25,000 patients. The narrower near-term-addressable method starts from a different question, not total disease burden but the population a launch plan can realistically reach: an ageing, predominantly male demographic with wild-type ATTR-CM (ATTRwt-CM), estimated at 2,000-5,000 patients and modelled directly in the AXLRx Launch Readiness assessment for pre-launch planning purposes. The two figures are not competing estimates of the same quantity. The 15,000-25,000 figure is the full HFpEF-adjacent burden across all ATTR-CM aetiologies; the 2,000-5,000 figure is a narrower, demographically-anchored subset built for near-term commercial addressability.

What explains why fewer than 1,000 patients are diagnosed against the broad estimate, and fewer than 300-400 against the narrower one, is diagnostic capacity, not case-finding effort. Tc-PYP scintigraphy, the non-invasive diagnostic standard for ATTR-CM, is available at fewer than 8 centres across all six GCC states, and most HFpEF patients are managed by general cardiologists without ATTR screening. That single constraint, not physician awareness or drug access, is why both the broad and the narrower estimate convert to a diagnosed population of under 5%. A separate hereditary subset, GCC-specific ATTRv carrying Arabian Peninsula variants (Ala97Ser, Glu89Gln), adds an estimated 500-1,000 patients tracked through the region's dedicated genetic registry, distinct from either wild-type estimate above.

Every AXLRx market sizing model triangulates at least two independent methods, in this case a broad HFpEF-misattribution-based burden estimate and a narrower demographically-anchored addressable cohort, and explains any gap as definitional scope rather than a measurement disagreement. This is explicitly a sizing model (static patient count), distinct from a Patient Flow or forecasting model (dynamic revenue/uptake).

ATTR amyloidosis GCC sizing sources: the GCC Cardiology Society ATTR task force 2023 report, Al-Tayeb A et al. (Amyloid 2020), the KFSH&RC ATTR genetic registry, and the AXLRx ATTR Amyloidosis GCC Launch Readiness assessment.