8,000-9,000 Americans have HAE, but only 35-40% are prophylaxed; the 2,500-4,000 never-prophylaxed patients are nearly as large a pool as the entire treated population.
Two sizing angles anchor the US HAE population, and they agree closely enough to triangulate with confidence. The epidemiology-based estimate applies a prevalence of roughly 1 in 50,000, a US HAE Association patient-advocacy figure rather than a peer-reviewed count, to the US population, implying 8,000 to 9,000 total patients. Independently, HAE Association member-survey and specialty-pharmacy data put the diagnosed and engaged population at roughly 6,000 to 10,000, a range that brackets the epidemiology-based estimate rather than contradicting it. Both methods point to the same order of magnitude, the confirmation a sizing model needs before the more commercially important question, treatment status, is layered on top.
Treatment status is where the real addressable-market question lives. Only 35 to 40 percent of the estimated population currently receives any prophylaxis, split roughly 45 percent lanadelumab and 20 percent berotralstat of the treated share, with the balance on C1-inhibitor replacement or the newer 2025 entrants. That leaves an estimated 2,500 to 4,000 patients who meet prophylaxis criteria, three or more attacks a year or a laryngeal history, but remain untreated, a population nearly as large as everyone currently on lanadelumab and berotralstat combined. A further 1,000 to 1,500 patients carry FXII-HAE or another normal-C1-INH variant that responds less predictably to standard kallikrein-targeted prophylaxis, a structurally underserved subgroup no current agent, approved or pipeline, has targeted directly.
US HAE sizing — total population against treatment status
| Sizing Method | Population Estimate | Source |
|---|---|---|
| Epidemiology-based (~1:50,000 prevalence) | 8,000-9,000 total patients | US HAE Association prevalence estimate |
| Diagnosed/engaged cross-check | 6,000-10,000 patients | HAE Association member survey; specialty-pharmacy data |
| Never-prophylaxed, attack-eligible | 2,500-4,000 patients | Derived from treatment-status segmentation |
| FXII-HAE / normal-C1-INH subpopulation | 1,000-1,500 patients | US HAE Association survey; published HAE variant literature |
Sources: US HAE Association member survey 2023; Zuraw BL, N Engl J Med 2008 (PMID 18768946); BioCryst investor day 2023 and berotralstat launch market analysis; Takeda HAE market research; Magerl M et al., Allergy 2019 (HAE variant types).
What this model answers
Every section answers a named commercial question your team is asking, scoped to your asset.
Delivers
- Epidemiology-based sizing methodology
- HAE Association member-survey cross-check
- the reconciled base-case total and its confidence range
Delivers
- 2,500-4,000 never-prophylaxed patient sizing
- treated-population share split (lanadelumab ~45%, berotralstat ~20%)
- sensitivity to prophylaxis-criteria definition
Delivers
- 1,000-1,500 patient subpopulation sizing
- mechanistic rationale for reduced response to kallikrein-targeted agents
- the addressable-market case for a differentiated mechanism
Custom model delivered in 72 hours.
Commission This ModelWhat's inside
- Why treatment status, not total prevalence, is the assumption that determines the addressable market
- Pressure-tested against the diagnosed-vs-epidemiology cross-check before the model is built out
- US prevalence rate (~1:50,000) applied to total population
- The 8,000-9,000 total-patient estimate this implies
- HAE Association member-survey and specialty-pharmacy data (6,000-10,000)
- Cross-check against the epidemiology-based estimate
- 35-40% prophylaxed, split by agent share (lanadelumab ~45%, berotralstat ~20%)
- The 2,500-4,000 never-prophylaxed addressable pool
- 1,000-1,500 patient sizing and mechanistic rationale
- Why this subgroup is structurally underserved by current agents
- The full triangulated model, re-runnable with your own assumptions
- The open sizing questions your team must close before the number is used in planning
Included with every brief
How AXLRx builds this model
Prepared by MoatRx analysts.
Every AXLRx market sizing model triangulates at least two independent methods, epidemiology-based and registry/survey-based, before accepting a patient count. This is explicitly a sizing model (static patient count), distinct from a Launch Readiness or forecasting model (dynamic revenue/uptake).
US HAE sizing sources: the US HAE Association member survey 2023, Zuraw BL (NEJM 2008, PMID 18768946) for prevalence and disease definition, BioCryst investor day 2023 and berotralstat market analysis for treated-share data, Takeda HAE market research, and Magerl M et al. (Allergy 2019) for HAE variant classification.
- US prevalence estimate (~1:50,000) and the 8,000-9,000 total-patient figure verified against the US HAE Association and Zuraw BL, NEJM 2008 (PMID 18768946)
- Diagnosed/engaged population range (6,000-10,000) and treated-share split verified against the US HAE Association member survey 2023 and BioCryst investor day 2023
- FXII-HAE/normal-C1-INH subpopulation size verified against Magerl M et al., Allergy 2019, and US HAE Association survey data
Frequently asked questions
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AXLRx delivers rare disease market sizing models built for forecasting and strategy teams sizing the US HAE opportunity. Custom model in 72 hours.
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Research-verified sizing model in 72 hours with optional analyst readout.