Key takeaways
- ~150,000 total US IgAN population implied by an adult incidence rate of 1.29–2.2 per 100,000/yr, the epidemiology-based ceiling
- 70,000–90,000 biopsy-confirmed US IgAN patients, the claims/registry-based count
- 15,000–25,000 high-risk treatment-eligible cohort (UPCR >1g/g, declining eGFR despite optimized ACEi/ARB±SGLT2i)
- 5,000–8,000 US patients currently on a novel IgAN therapy, roughly 30–50% of the high-risk eligible cohort
Three numbers, not one: an estimated 150,000 total US IgAN patients, 70,000 to 90,000 biopsy-confirmed, and 5,000 to 8,000 on novel therapy today, each gap between them separately sized and addressable.
Sizing the US IgA nephropathy market starts from incidence, not prevalence, because IgAN is a slow-accumulating disease with a long undiagnosed tail. Adult primary IgAN incidence runs 1.29 to 2.2 new cases per 100,000 people a year in a racially and ethnically diverse US population, highest in patients of Asian ancestry and lowest in Black patients. Compounded over the decades-long course typical of the disease, that incidence rate implies a total US IgAN population of roughly 150,000. That figure is a modeled ceiling, not a diagnosed count: it is the epidemiology-based method, and it disagrees on purpose with the claims-based method below.
The claims-based method counts what payers and registries actually see: an estimated 70,000 to 90,000 US patients carry a biopsy-confirmed IgAN diagnosis. The gap between 150,000 and that biopsy-confirmed figure, on the order of 60,000 to 80,000 patients, has a specific, sourced cause rather than model error. Diagnosis requires a kidney biopsy, and a meaningful share of milder disease is instead managed simply as chronic kidney disease without ever reaching a nephrologist or a biopsy needle. Within the biopsy-confirmed pool, only a high-risk segment, 15,000 to 25,000 patients with UPCR above 1g/g and declining eGFR despite optimized ACEi/ARB and SGLT2i background therapy, is the near-term addressable population for a disease-modifying agent, and just 5,000 to 8,000 of those patients are on a novel therapy today. That last gap is a penetration problem, not a sizing problem, and our sensitivity analysis ranks it separately from the diagnostic gate above.
US IgA nephropathy sizing — epidemiology versus claims-based triangulation
| Sizing Method | Population Estimate | Source |
|---|---|---|
| Epidemiology-based (incidence-derived) | ~150,000 total US IgAN patients | American Journal of Nephrology incidence study (PMID 39496243) |
| Claims/registry-based (biopsy-confirmed) | 70,000–90,000 patients | IQVIA IgAN claims database analysis |
| High-risk treatment-eligible | 15,000–25,000 patients (UPCR >1g/g, declining eGFR) | Derived from claims-based segmentation criteria |
| On novel therapy today | 5,000–8,000 patients | IQVIA IgAN market data |
Sources: American Journal of Nephrology diverse-population incidence study (PMID 39496243); IQVIA IgAN market data 2024 and claims database analysis 2023; Nature Reviews Disease Primers IgAN (PMID 27189177).
What this model answers
Every section answers a named commercial question your team is asking, scoped to your asset.
- Why does the epidemiology-based total (~150,000) run so far ahead of the biopsy-confirmed claims count (70,000-90,000), and is the gap addressable? • Incidence-to-prevalence modeling methodology • the biopsy-dependency diagnostic gate • what share of the undiagnosed gap is reachable with expanded biopsy referral versus permanently missed
- Within the biopsy-confirmed pool, how is the 15,000-25,000-patient high-risk treatment-eligible cohort defined, and why is it smaller than the full diagnosed population? • UPCR and eGFR segmentation criteria • the ACEi/ARB and SGLT2i optimization gate that precedes eligibility • cohort sizing methodology
- Which single assumption moves the sized total more: incidence rate, biopsy rate, or the UPCR eligibility threshold? • Sensitivity ranking across every input • the assumption most likely to move the total under a challenge meeting • scenario ranges tied to biopsy-rate and threshold changes
What's inside
-
1 · The Binding Constraint 2 pp
- Why biopsy-dependency, not incidence rate, decides how much of the true US IgAN population is ever counted
- Pressure-tested against the epidemiology-vs-claims gap before the rest of the model is built out
-
2 · Epidemiology-Based Sizing 3 pp
- Adult US incidence of 1.29-2.2 per 100,000/yr by race and ethnicity
- The ~150,000-patient total population this incidence rate implies
-
3 · Claims and Registry-Based Sizing 3 pp
- The 70,000-90,000 biopsy-confirmed patient count
- Cross-check against the epidemiology-based estimate
-
4 · Triangulation & the Undiagnosed Gap 3 pp
- Where the two methods agree and diverge
- The biopsy-dependency diagnostic gate as the explanation for the gap
-
5 · High-Risk Treatment-Eligible Segmentation 3 pp
- UPCR >1g/g and declining-eGFR criteria that define the 15,000-25,000 cohort
- The 5,000-8,000-patient novel-therapy penetration rate within that cohort
-
6 · Sensitivity Analysis 3 pp
- Ranking incidence rate, biopsy rate, and UPCR threshold by impact on the total
- Scenario ranges tied to biopsy-referral expansion
-
7 · Client Alignment Questions 2 pp
- The open sizing questions your team must close before the number is used in planning
Appendix and source ledger included · 45-minute analyst readout included with delivery
Custom model delivered in 72 hours.
Assess this reportIncluded with every brief
Get Started
Commission this model
AXLRx delivers US IgA nephropathy market sizing models built for forecasting and strategy teams sizing the treatment-eligible opportunity. Custom model in 72 hours.
- 1. Submit your requestSpecify your indication, market, and cohort definition.
- 2. Scoping callAXLRx analyst confirms triangulation methods and comparator set before building.
- 3. DeliveryResearch-verified sizing model in 72 hours with optional analyst readout.
How AXLRx builds this model
Prepared by MoatRx analysts on the AXLRx commercial consulting engine.
Every AXLRx market sizing model triangulates at least two independent methods, epidemiology-based and claims/registry-based, before accepting a patient count. This is explicitly a sizing model of a static patient count, distinct from a forecasting or patient-flow model of dynamic uptake.
US IgA nephropathy sizing sources: the American Journal of Nephrology diverse-population incidence study (PMID 39496243), IQVIA IgAN market data 2024 and claims database analysis 2023, and Nature Reviews Disease Primers on IgAN progression risk (PMID 27189177).
- US incidence rate and racial/ethnic variation verified against the American Journal of Nephrology diverse-population study (PMID 39496243)
- Biopsy-confirmed patient count and novel-therapy penetration verified against IQVIA IgAN claims database analysis
- High-risk cohort segmentation criteria verified against published UPCR and eGFR progression-risk thresholds (PMID 27189177)
Frequently asked questions
Deliverables What formats are included with every model?
Every commissioned Market Sizing Model includes an editable 7-sheet Excel model (Cover, Epidemiology-Based Sizing, Claims-Based Sizing, Triangulation, High-Risk Segmentation, Sensitivity, Sources) and a PDF methodology brief. There is no PowerPoint deck, since a sizing model is built to be worked in directly rather than presented from. An optional 45-minute analyst readout call is included.
Sources How is the patient count verified?
AXLRx triangulates every sizing estimate across at least two independent methods, epidemiology-based and claims/registry-based. No single-source number ships unverified.
Customisation Can I size a specific subpopulation or comparator cohort?
Yes. The intake form captures your indication, target market, and cohort definition. A scoping call confirms scope before research starts.