The Unmet Need in IgAN and FSGS
IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS) are two of the most significant glomerular causes of chronic kidney disease and end-stage renal disease (ESRD) worldwide, each defined by progressive proteinuria, eGFR decline, and a historical absence of disease-modifying approved therapies. Approximately 20–50% of IgAN patients progress to ESRD within 20–30 years, according to disclosures in retrieved patent filings — a statistic that underscores the scale of unmet clinical need driving the current wave of innovation.
IgAN pathobiology is described in multiple retrieved patents as a “two-hit” process: aberrantly galactose-deficient IgA1 (Gd-IgA1) acts as a self-antigen, triggering autoantibody formation and immune complex deposition in the mesangial region, followed by complement activation, mesangial cell proliferation, and progressive glomerular injury. FSGS, by contrast, is characterised by primary podocyte injury and depletion, with circulating permeability factors — most prominently soluble urokinase plasminogen activator receptor (suPAR) — identified as pathogenic mediators. Despite distinct aetiologies, both diseases converge on complement dysregulation as a shared mechanistic vulnerability, a convergence that is shaping the current patent landscape.
In IgAN, aberrantly galactose-deficient IgA1 (Gd-IgA1) acts as a self-antigen, triggering autoantibody formation and immune complex deposition in the mesangial region. This is followed by complement activation, mesangial cell proliferation, and progressive glomerular injury — a sequence described across multiple retrieved patent filings as the disease’s defining pathogenic cascade.
Genetic risk factors also modulate disease susceptibility: APOL1 variants are cited in Genzyme filings as modifying disease risk in primary FSGS, pointing toward a precision medicine stratification opportunity that remains underexploited in current clinical practice. According to WHO global burden data, chronic kidney disease affects approximately 10% of the global population, making the development of effective glomerular disease therapies a public health priority.
Approximately 20–50% of IgA nephropathy (IgAN) patients progress to end-stage renal disease (ESRD) within 20–30 years, according to disclosures in retrieved patent filings from commercial and academic assignees.
Complement Pathway Inhibition: MASP-2 and the Alternative Pathway
Complement pathway inhibition — particularly via MASP-2 and alternative pathway targets — represents the single largest mechanistic cluster in the retrieved patent dataset for IgAN and FSGS. The University of Leicester, in partnership with Omeros Corporation, has filed an extensive international patent portfolio spanning at least 9 jurisdictions (WO, AU, US, CA, CN, SG, JP, MX, ES, and OA) covering anti-MASP-2 monoclonal antibodies for IgAN and related proteinuric glomerular diseases.
The University of Leicester and Omeros Corporation hold at least 12 retrieved patent records covering MASP-2 inhibitory antibodies for IgAN and related glomerular diseases, spanning 9+ jurisdictions — the most geographically comprehensive complement-directed IP estate in the retrieved dataset.
MASP-2 (Mannose-Binding Lectin-Associated Serine Protease-2) mediates lectin pathway complement activation. The key mechanistic claim across Leicester/Omeros filings is selective inhibition of MASP-2-dependent complement activation while leaving the classical C1q-dependent pathway intact — a specificity that may reduce immunosuppressive off-target effects compared with broader complement inhibitors. Retrieved claims describe reduction of renal tubulointerstitial inflammation, anti-fibrotic effects demonstrated in the unilateral ureteral obstruction (UUO) mouse model, and proteinuria reduction as primary endpoints. Dosing regimens described include intravenous administration at approximately 4 mg/kg once weekly for at least 12 weeks, targeting MASP-2 epitopes defined by SEQ ID NO:67 (heavy chain) and SEQ ID NO:70 (light chain).
“MASP-2 inhibition selectively blocks lectin pathway complement activation while leaving the classical C1q-dependent pathway intact — a specificity that may reduce immunosuppressive off-target effects compared with broader complement inhibitors.”
Beyond MASP-2, the alternative complement pathway (CAP) is targeted by multiple assignees. Alexion Pharmaceuticals (AstraZeneca) has filed patents in CN and MX describing kidney-active fusion proteins containing Factor H catalytic domains — including VHH (single-domain camelid antibody) elements and Factor H-related protein 5 (FHR5) domain constructs — specifically naming FSGS, IgAN, MCD, and C3 glomerulopathy as target diseases. Q32 Bio has filed WO and TW patents covering compounds targeting renal diseases characterised by complement system dysregulation and/or C3d deposition, with preclinical data shown in the Passive Heymann Nephritis (PHN) model. Novartis has filed a CN patent describing iptacopan (a Factor B inhibitor) for IC-MPGN, expanding the alternative pathway inhibitor landscape in nephrology. Celldex Therapeutics has separately filed for soluble complement receptor type 1 (sCR1) targeting C3 deposition in kidney tissue.
Explore the full MASP-2 and complement inhibition patent landscape with PatSnap Eureka.
Search Complement Inhibition Patents in PatSnap Eureka →SGLT2 Inhibitors and the Hemodynamic Renoprotection Thesis
SGLT2 inhibitors — particularly dapagliflozin and empagliflozin — represent the most commercially advanced renoprotective modality in the retrieved dataset, with patent claims explicitly extending to non-diabetic IgAN and FSGS-associated CKD. AstraZeneca has filed patents in CN and JP for dapagliflozin specifically in CKD patients with and without type 2 diabetes, with explicit indication extensions to IgAN-associated CKD, CKD related to chronic glomerulonephritis, and FSGS-associated proteinuric CKD.
The mechanistic rationale for SGLT2 inhibition in glomerular disease rests on three complementary effects: reduction of intraglomerular pressure via tubuloglomerular feedback (a hemodynamic mechanism), anti-inflammatory effects, and anti-fibrotic properties. AstraZeneca’s JP patent (2023) explicitly references treatment of “IgA nephropathy (also known as Berger’s disease)” in the context of CKD methods in patients without type 2 diabetes — a regulatory filing strategy consistent with the broader DAPA-CKD program context cited in the filing. Boehringer Ingelheim has filed multiple patents covering empagliflozin for CKD prevention in periadiposity-related glomerulosclerosis and IgAN across CN, HK, and TW jurisdictions.
AstraZeneca’s patent filings for dapagliflozin explicitly extend to IgAN-associated CKD and FSGS-associated proteinuric CKD in patients without type 2 diabetes, positioning SGLT2 inhibition as a disease-modifying strategy beyond its original diabetic nephropathy indication.
A Taiwanese National Defense Medical College patent identifies SGLT2 expression itself as a biomarker for diagnosing CKD and monitoring treatment response in FSGS and IgAN — a signal that SGLT2 may have diagnostic as well as therapeutic utility in these conditions. Joslin Diabetes Center has filed CN and JP patents proposing SGLT2 inhibitors as indicated therapy when patients are identified through FGF20, ANGPT1, or TNFSF12 biomarker screening as being at risk of progressive renal decline, representing an emerging precision medicine framework for CKD progression prevention. This type of biomarker-guided approach aligns with broader trends in personalised medicine described by NIH and EMA for stratified trial design in nephrology.
Endothelin Antagonism, suPAR Targeting, and Novel Biologics
Beyond complement inhibition and SGLT2, the retrieved dataset reveals several additional mechanistic pillars — each with distinct assignee profiles and translational maturity. Chinook Therapeutics (acquired by Novartis) has filed patents in CN and JP covering atrasentan, a selective endothelin-A receptor antagonist, for both IgAN and FSGS. Claimed endpoints include reduction of renal inflammation and fibrosis, proteinuria reduction, eGFR stabilisation, reduction of ESRD onset, and reduction of disease flares. The specificity of dosing language, patient exclusion criteria, and clinical endpoints in Chinook’s filings is consistent with an active Phase II/III clinical development programme.
The mechanistic basis for atrasentan in IgAN involves inhibition of ET-A-mediated mesangial cell activation, with downstream suppression of the PDGF pathway — specifically PIK3R1, PDGFRA, and NFKB1 — reducing glomerular inflammation and fibrosis. This mesangial PDGF pathway component is cited as a mechanistic component in IgAN mesangial cells across multiple Chinook filings.
Soluble urokinase plasminogen activator receptor (suPAR) is identified in the retrieved dataset as a circulating pathogenic factor uniquely elevated in FSGS — not other primary glomerular diseases. Its downstream target is podocyte β3 integrin, activation of which drives proteinuria and glomerulosclerosis. At least four distinct assignees are independently pursuing suPAR-directed strategies: Walden Biosciences, the University of California (Regents), the University of Miami, and Massachusetts General Hospital.
Walden Biosciences has filed WO and JP patents (as recently as 2025) for isolated antibodies binding suPAR for glomerular kidney diseases including FSGS, IgAN, lupus nephritis, and membranous nephropathy. The University of California holds a pending US patent covering anti-uPAR/CD87 and anti-suPAR antibodies specifically for FSGS treatment and prevention. The University of Miami holds an active JP patent demonstrating that ex vivo suPAR removal from circulation can halt or slow disease onset by preventing podocyte β3 integrin activation, with comparison of suPAR levels pre- and post-treatment as a clinical endpoint.
Novel biologic targets are also emerging in the podocyte biology space. Everest Medicines (China) has filed WO and CN patents for anti-SLIT2 antibodies targeting FSGS, glomerular disease, and proteinuria, with podocyte function preservation as a stated endpoint. Boehringer Ingelheim has filed WO and TW patents for TRPC6 (transient receptor potential cation channel C6) inhibitors — a channel expressed in podocytes — for FSGS treatment. ChemoCentryx (now Amgen) holds active JP patents for C5aR antagonists (including avacopan-class molecules) for FSGS treatment across primary, secondary, and genetic subtypes. The growing interest in podocyte ion channel biology reflected in these filings aligns with research priorities identified by organisations such as National Kidney Foundation for glomerular disease drug development.
For IgAN specifically, MorphoSys (now Novartis) has filed a CN patent for anti-CD38 antibodies (including felzartamab/MOR202), with the mechanism involving depletion of CD38-expressing antibody-secreting plasma cells and reduction of circulating immune complexes and mesangial IgA deposits. Westlake Biosciences has filed a CN patent for anti-APRIL antibodies for IgAN, exploiting the role of APRIL (a proliferation-inducing ligand) in driving pathological IgA production. These B-cell and plasma cell-directed approaches represent a distinct immunological axis from complement and SGLT2 strategies.
In IgA nephropathy, anti-CD38 antibodies such as felzartamab (MOR202, filed by MorphoSys/Novartis) act by depleting CD38-expressing antibody-secreting plasma cells and reducing circulating immune complexes and mesangial IgA deposits — a mechanism distinct from complement inhibition or SGLT2 blockade.
Combination Strategies and Precision Medicine Directions
The most strategically significant signal emerging from the retrieved dataset is the shift toward combination therapy patents and biomarker-guided precision frameworks — a shift that suggests single-agent studies alone may not define the eventual standard of care in IgAN or FSGS. AstraZeneca’s 2025 CN patent for a fixed-dose combination (FDC) of zibotentan (endothelin receptor antagonist) and dapagliflozin (SGLT2 inhibitor) for high-proteinuria CKD is the most advanced combination patent in the dataset, explicitly covering biopsy-confirmed IgAN and FSGS indications.
The mechanistic rationale for the zibotentan/dapagliflozin FDC combines dual hemodynamic effects from SGLT2 inhibition (reducing intraglomerular pressure via tubuloglomerular feedback) with anti-inflammatory and anti-fibrotic effects from ET-A blockade — an additive renoprotective profile that neither agent is claimed to achieve alone in high-proteinuria populations. IP teams and competitors should monitor this FDC for Freedom-to-Operate considerations given its explicit IgAN and FSGS claim scope.
“Combination therapy IP — ERA+SGLT2, MASP-2+steroid sparing, BET+SGLT2 — is emerging as the next frontier in this patent landscape, suggesting that single-agent studies alone may not define the eventual standard of care.”
Multiple University of Leicester/Omeros filings reference co-administration strategies permitting corticosteroid dose reduction, pointing toward a steroid-sparing combination strategy for steroid-dependent IgAN. Retrieved CN and AU filings from the University of Leicester also describe anti-MASP-2 antibodies as an adjunct to renal replacement therapy — reducing dialysis or plasmapheresis frequency, or as bridge therapy in transplant candidates — a potentially high-value perioperative strategy.
Resolute Biosciences’ TW patent describes a combination of a BET bromodomain inhibitor with an SGLT2 inhibitor for improving eGFR in kidney disease, representing an emerging epigenetic plus SGLT2 combination approach. Joslin Diabetes Center’s biomarker-guided framework (FGF20, ANGPT1, TNFSF12 screening combined with SGLT2 inhibitor therapy) signals an emerging precision medicine architecture for CKD progression prevention that goes beyond empirical prescribing. These developments are consistent with the precision nephrology frameworks being developed under initiatives tracked by WIPO‘s global health innovation reporting.
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Analyse IgAN and FSGS Combination Patents in PatSnap Eureka →Patent Landscape: Assignees, IP Density, and Strategic Implications
Patent activity in the retrieved dataset is dominated by a relatively small set of commercial and academic assignees, with the University of Leicester/Omeros Corporation holding the most geographically comprehensive IP estate and AstraZeneca occupying the most commercially advanced position in the SGLT2 space. The landscape also reveals several strategically significant gaps and emerging consolidation opportunities.
Dominant Assignees by Mechanistic Focus
- University of Leicester / Omeros Corporation — At least 12 retrieved records covering MASP-2 inhibitory antibodies across 9+ jurisdictions (WO, AU, US, CA, CN, SG, JP, MX, ES, OA). The most geographically comprehensive complement-directed IP estate in the dataset, spanning IgAN, lupus nephritis, renal fibrosis, and FSGS.
- AstraZeneca (Sweden) AB — Active in SGLT2 inhibition (dapagliflozin) and ERA combination (zibotentan + dapagliflozin) for CKD with IgAN and FSGS indications across CN and JP filings.
- Boehringer Ingelheim International GmbH — Active in SGLT2 inhibitor filings (empagliflozin) across human CKD (IgAN, periadiposity FSGS) and TRPC6 inhibitors for FSGS across CN, HK, TW, WO, and TW jurisdictions.
- Chinook Therapeutics (Novartis) — Active ERA strategy with atrasentan in IgAN and FSGS across CN and JP, with filings as recent as 2025.
- Alexion Pharmaceuticals (AstraZeneca) — Filed in CN and MX for complement alternative pathway fusion proteins targeting FSGS, IgAN, and related glomerulopathies.
- ChemoCentryx (Amgen) — Multiple active JP patents for C5aR/Formula I compounds in FSGS.
- Walden Biosciences — WO and JP patents for anti-suPAR antibodies across FSGS, IgAN, and related kidney diseases (filings as recent as 2025).
- Q32 Bio — WO and TW patents for complement dysregulation-targeted compounds with C3d deposition as a biomarker criterion.
Strategic Implications
Complement inhibition remains the most heavily patent-protected space in IgAN, with the Leicester/Omeros MASP-2 estate spanning at least 9 jurisdictions and encompassing both proteinuria reduction and anti-fibrotic claims. New entrants must design around the MASP-2 epitope claims (SEQ ID NO:67/70) and the broader MASP-2-dependent complement activation mechanism, or differentiate through alternative pathway targets such as Factor B, Factor H, or C3.
The suPAR targeting space in FSGS is fragmented but biologically well-supported, with at least four distinct assignees pursuing independent approaches to suPAR neutralisation or depletion. Consolidation or licensing activity in this space could be strategically valuable given the orthogonal mechanism relative to complement and SGLT2 approaches. APOL1-genotype-stratified FSGS therapy (TGFβ antagonism via fresolimumab, Genzyme/Sanofi) represents a precision medicine niche with limited competition in this dataset; the absence of an approved FSGS pharmacotherapy despite extensive IP activity underscores ongoing unmet need and potential first-mover advantages for agents advancing through stratified trial designs.
The suPAR targeting space in FSGS is fragmented across at least four independent assignees — Walden Biosciences, the University of California, the University of Miami, and Massachusetts General Hospital — each pursuing distinct antibody or depletion strategies, with no single dominant IP holder as of the retrieved dataset.
Overall activity in the retrieved dataset is predominantly patent-driven with limited academic literature records, suggesting commercial IP development is more prominently captured than basic research outputs. This is consistent with the observation that nephrology drug development has historically lagged behind oncology and cardiovascular medicine in clinical trial volume, a gap noted in analyses published by NEJM and the broader nephrology community.