Takes From IgAN KOL Dinner -- Large TAM & Positive Outlook For BAFF/APRILs

Research evidence excerpt

Takes From IgAN KOL Dinner -- Large TAM & Positive Outlook For BAFF/APRILs

USA | Biotechnology EquityJuneResearch21, 2026

Takes From IgAN KOL Dinner -- Large TAM &

Positive Outlook For BAFF/APRILs

We hosted KOL Dr. Krzysztof Kiryluk (Chief of Nephrology @Columbia

University) and discussed the evolving IgAN treatment paradigm, BAFF/APRIL

drug (sibeprenlimab, atacicept, povetacicept, zigakibart) profiles, new interim

sibeprenlimab eGFR data @ERA meeting, and other MOAs being pursued for

IgAN.

KOL is the Chief of Columbia University’s Division of Nephrology overseeing one of the

largest (many pt referrals) academic IgAN/glomerular practices in the U.S. His center strongly

favors proximal immunomodulatory BAFF/APRIL agents over reno-protective ERA/ARB as 1L

tx in IgAN, citing robust genetic validation of the APRIL/TACI pathway and pot'l for disease

modification rather than symptom mgmt. He emphasized cross-trial comparisons as problematic,

and differentiation among BAFF/APRILs (sibeprenlimab, atacicept, povetacicept and zigakibart) is

unclear based on available data. We note that a lot of IgAN pts are tx'd at community clinics where

tx framework is likely different.

KOL noted underdiagnosis remains a major constraint as kidney biopsy is required for IgAN.

We note NVS' latest IgAN U.S. epi data for 2026 showed ~92K biopsy-diagnosed pts (~85K adults) w/

~60K tx'd and ~51K w/ persistent UPCR (which translates to ~$20B assuming Otsuka-like pricing). W/

effective drugs now available, nephrologists are becoming more aggressive about biopsying earlier.

He further noted Gd-IgA1 is not a reliable biomarker (elevated in ~75% of IgAN pts, and not specific)

and unmet need remains for reliable non-invasive biomarkers to unlock full TAM pot'l, analogous

to PLA2R for PMN.