Rare Disease · United States · In-Market

US IgA Nephropathy Competitive Intelligence

From zero disease-specific drugs to five in three years: how endothelin, complement and APRIL inhibitors are redrawing the IgAN market.

~1.29–2.2 new cases per 100,000/yr (US)5 FDA-approved therapiesIn-MarketUpdated Q3 2026
Market United States GCC (Gulf) United Kingdom Stage
The Landscape

Five FDA-approved therapies across four mechanisms now compete in a market that had none in 2021 — and 30–40% of patients still progress to kidney failure without disease modification.

Until December 2021, no therapy was approved specifically for IgA nephropathy; management rested on renin-angiotensin system (RAS) blockade and blood-pressure control. By mid-2026 the FDA had approved five disease-specific agents across four mechanisms: targeted-release budesonide (Tarpeyo, Calliditas/Otsuka), the dual endothelin-A/angiotensin receptor antagonist sparsentan (Filspari, Travere), the selective endothelin-A antagonist atrasentan (Vanrafia, Novartis), the oral factor B / alternative-complement inhibitor iptacopan (Fabhalta, Novartis), and the first-in-class anti-APRIL monoclonal antibody sibeprenlimab (Voyxact, Otsuka). Four are oral; sibeprenlimab is a self-administered subcutaneous injection.

Every agent won accelerated approval on reduction of proteinuria (the surrogate the FDA accepts as reasonably likely to predict benefit), and targeted-release budesonide and sparsentan have since added eGFR-slope confirmation. The commercial contest is now between mechanisms: does a prescriber layer an endothelin antagonist, a complement inhibitor or an APRIL inhibitor onto optimized supportive care (RAS blockade plus an SGLT2 inhibitor)? IgA nephropathy still carries a 30–40% lifetime risk of progression to end-stage kidney disease, and the RaDaR registry reports median kidney survival of roughly 11 years from diagnosis — the clinical urgency that underwrites the launch wave.

5
FDA-approved IgAN-specific therapies as of 2026, up from zero in 2021 · Drugs@FDA
30–40%
of IgAN patients progress to end-stage kidney disease over 20–30 years · Nat Rev Dis Primers (PMID 27189177)
51.2%
sibeprenlimab proteinuria reduction vs placebo at 9 months, VISIONARY · NEJM (PMID 41211929)
DRUG LANDSCAPE

FDA-approved IgA nephropathy therapies — United States, 2026

Drug (Brand / INN)MechanismCompanyUS ApprovalKey Trial ResultRoute / Access
Filspari (sparsentan)Dual endothelin-A + angiotensin receptor antagonistTravereAccelerated Feb 2023; full Sep 2024PROTECT: UPCR −49.8% vs −15.1% irbesartan at 36 wk; eGFR-slope benefit at 2 yrOral; REMS (hepatotoxicity); Part D
Tarpeyo (budesonide, targeted-release)Gut-directed corticosteroid; lowers Gd-IgA1Calliditas / OtsukaAccelerated Dec 2021; full Dec 2023NefIgArd: 2-yr eGFR benefit +5.05 mL/min/1.73m² vs placeboOral 9-month course; Part D
Fabhalta (iptacopan)Oral factor B / alternative-complement inhibitorNovartisAccelerated Aug 2024APPLAUSE-IgAN: UPCR 38.3% lower vs placebo at 9 moOral; Part D
Vanrafia (atrasentan)Selective endothelin-A antagonistNovartisAccelerated Apr 2025ALIGN: UPCR −38.1% vs −3.1% placebo at 36 wkOral; no REMS; Part D
Voyxact (sibeprenlimab)Anti-APRIL monoclonal antibody (first-in-class)OtsukaAccelerated Nov 2025VISIONARY: UPCR 51.2% lower vs placebo at 9 moSC self-administered q4w; Part D

Sources: FDA Drugs@FDA (approval status and dates); PROTECT, Lancet 2023 (PMID 37015244; 37931634); NefIgArd, Lancet 2023 (PMID 37591292); APPLAUSE-IgAN, NEJM 2024 (PMID 39453772); ALIGN, NEJM 2024 (PMID 39460694); VISIONARY, NEJM 2025 (PMID 41211929). Sibeprenlimab approval per Otsuka; openFDA listing pending.

Commercial Questions

What this brief answers

Every section answers a named commercial question your team is asking, scoped to your asset.

01
With five approved agents across four mechanisms, how do endothelin antagonists, complement inhibitors, the APRIL inhibitor and targeted budesonide differentiate on efficacy, dosing and positioning?

Delivers

  • • Proteinuria reduction across PROTECT, NefIgArd, APPLAUSE-IgAN, ALIGN and VISIONARY • eGFR-slope evidence: which agents have confirmatory kidney-function data vs proteinuria-only accelerated approval • Oral vs subcutaneous administration and dosing cadence by product • Mechanistic positioning: where each class fits on optimized supportive care (RAS blockade + SGLT2i)
02
How are US payers gating access — biopsy confirmation, proteinuria and eGFR thresholds, RASi/SGLT2i step-through, and the Filspari REMS?

Delivers

  • • Representative commercial and Part D prior-authorization criteria by product • Proteinuria and eGFR entry thresholds and required duration of optimized RAS blockade ± SGLT2i • Pharmacy-benefit (Part D) routing for all five patient-administered agents • Filspari REMS hepatotoxicity monitoring and its access friction vs REMS-free competitors
03
What do the pipeline through 2027–2028 and the ICER 2026 review mean for the durability of the current leaders?

Delivers

  • • Phase 3 anti-APRIL and BAFF/APRIL agents: zigakibart (Novartis), atacicept (Vera), telitacicept (RemeGen) — mechanism, trial ID, expected readout • Terminal complement (ravulizumab) Phase 3 status • ICER 2026 IgAN assessment: cost-effectiveness estimates and the CTAF review timeline • eGFR confirmatory readouts that could convert accelerated approvals and reset payer posture

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Contents

What's inside

Rare Disease · 24–32 pp · In-Market · Analyst report + Excel model + PowerPoint readout

1 Market Map & the 2021→2026 Approval Wave 4 pp
  • Before December 2021, no therapy was approved specifically for IgA nephropathy; management relied solely on RAS blockade.
  • Why five FDA-approved agents across four mechanisms now exist, up from zero disease-specific therapies just five years ago.
2 Drug Profiles: Endothelin, Complement, APRIL & Budesonide 8 pp
  • PROTECT trial data show sparsentan reducing proteinuria by 49.8% versus 15.1% for irbesartan at 36 weeks.
  • Why sibeprenlimab, the first-in-class anti-APRIL antibody, cut proteinuria 51.2% versus placebo in the VISIONARY trial.
3 Proteinuria vs eGFR — the Evidence Standard 4 pp
  • Why every approved IgAN agent won accelerated approval on proteinuria reduction, the FDA's accepted surrogate endpoint.
  • Only budesonide and sparsentan have since added confirmatory eGFR-slope data, with Tarpeyo showing a 5.05 mL/min/1.73m2 benefit.
4 US Payer Access, PA Criteria & the Filspari REMS 5 pp
  • Why Filspari's REMS hepatotoxicity monitoring requirement creates access friction versus its REMS-free competitor atrasentan.
  • All five IgAN agents route through Medicare Part D, from four oral products to sibeprenlimab's subcutaneous every-4-week injection.
5 KDIGO 2025 & Treatment Sequencing 3 pp
  • The KDIGO 2025 IgAN/IgAV guideline update now governs how prescribers sequence the five new mechanisms.
  • A 30-40% lifetime risk of end-stage kidney disease and an 11-year median kidney survival underpin the urgency behind treatment sequencing.
6 Pipeline & the ICER 2026 Review 3 pp
  • Phase 3 pipeline agents zigakibart, atacicept, and telitacicept target the same APRIL/BAFF pathway as sibeprenlimab.
  • Why the ICER 2026 IgA nephropathy review's cost-effectiveness verdict could reset payer posture across all five approved agents.
Appendix and source ledger included · 45-minute analyst readout included with delivery
Formats

Included with every brief

PDF
PDF Brief
US IgA Nephropathy CI Brief — Complete Edition
25–30 page analyst brief: five-agent competitive map across endothelin, complement, APRIL and budesonide mechanisms, the evidence standard, US payer access, KDIGO 2025 sequencing and pipeline.
XLS
Excel Model
Drug Comparison & Payer Grid
Drug-by-drug comparison (mechanism, trial, proteinuria/eGFR result, approval), payer PA criteria, and market statistics in editable Excel.
PPT
PowerPoint
Executive Readout — PowerPoint
12–15 slide readout deck for commercial team presentations, formatted to AXLRx design standards.
Methodology

How AXLRx builds this brief

Prepared by MoatRx analysts.

Every AXLRx brief is built from primary regulatory sources (FDA Drugs@FDA, ClinicalTrials.gov), peer-reviewed literature, and live payer policy documentation — not secondary summaries, market-research reports, or unverified estimates. Findings are independently verified before inclusion; if a figure cannot be sourced to a live record, it does not ship.

US IgA nephropathy Competitive Intelligence sources: FDA Drugs@FDA (approval status and dates), primary trial publications in the Lancet and the New England Journal of Medicine (PROTECT, NefIgArd, APPLAUSE-IgAN, ALIGN, VISIONARY), ClinicalTrials.gov pipeline registrations, the KDIGO 2025 IgAN/IgAV guideline, the ICER 2026 IgA nephropathy assessment, and US epidemiology from the American Journal of Nephrology and the RaDaR registry (CJASN).

  • PROTECT sparsentan results verified against Lancet primary publications (PMID 37015244 interim; PMID 37931634 two-year)
  • NefIgArd, APPLAUSE-IgAN, ALIGN and VISIONARY results verified against primary publications (PMID 37591292; 39453772; 39460694; 41211929)
  • US incidence and racial variation verified against the American Journal of Nephrology diverse-population study (PMID 39496243)
  • Long-term progression benchmark verified against the RaDaR registry, CJASN (PMID 37055195)
FAQ

Frequently asked questions

Landscape
How many therapies are approved for IgA nephropathy in the US?
As of 2026, five FDA-approved IgAN-specific therapies are available: targeted-release budesonide (Tarpeyo), sparsentan (Filspari), atrasentan (Vanrafia), iptacopan (Fabhalta) and sibeprenlimab (Voyxact) — spanning gut-directed corticosteroid, endothelin-A antagonism, alternative-complement inhibition and APRIL inhibition. All five won accelerated approval on proteinuria reduction; Tarpeyo and Filspari have added eGFR confirmation.
Access
How do US payers decide who can start an IgA nephropathy therapy?
Representative commercial and Medicare Part D policies require biopsy-confirmed primary IgAN, eGFR generally ≥30 mL/min/1.73m², a proteinuria threshold (often UPCR ≥0.8–1.5 g/g), and a documented trial of optimized renin-angiotensin blockade (increasingly with an SGLT2 inhibitor) before a disease-specific agent is covered. All five agents are patient-administered and route through the pharmacy benefit; sparsentan additionally requires REMS enrollment for hepatotoxicity monitoring.
Deliverables
What formats are included with every brief?
Every commissioned brief includes three deliverables: a 20–30 page PDF analyst brief with verified sources and exhibit tables, an editable Excel model, and a 10–15 slide PowerPoint readout deck. An optional 60-minute analyst readout call is included with all deliveries.
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