Visionary Study: Phase 3 Trial of Sibeprenlimab in Immunoglobulin A Nephropathy (IgAN)

Inclusion Criteria:

- Male and female patients ≥ 18 years of age .

- Biopsy-confirmed IgAN. (Patients with an eGFR of 30 to 45 mL/min/1.73m2 must have
had a kidney biopsy performed within 36 months of the screening visit).

- Stable and maximally tolerated dose of ACEI and/or ARB for at least 3 months prior
to screening. Patients who are on a stable dose of SGLT2i may participate if
treatment was initiated ≥3 months prior to screening. Patients who are unable to
take an ACEI or ARB may participate if their overall management conforms with
standards of care and other protocol requirements.

- Screening urine protein/creatinine ratio (uPCR) ≥ 0.75 g/g or urine protein ≥ 1.0
g/day

- eGFR ≥ 30 mL/min/1.73 m2, (for the exploratory cohort only: eGFR 20- <30 mL/min/1.73
m2), calculated using the CKD-EPI equation.)

Exclusion Criteria:

- Secondary forms of IgAN or IgA vasculitis.

- Coexisting chronic kidney disease other than IgAN.

- Kidney biopsy findings in addition to IgAN including those of diabetic nephropathy,
membranous nephropathy, or lupus nephritis. Hypertensive vascular changes are
acceptable.

- Kidney biopsy MEST or MEST-C score of T2 or C2 (Oxford IgAN classification). If
MEST-scoring was not performed, the presence of > 50% tubulo-interstitial fibrosis,
or crescents in > 25% of glomeruli is exclusionary. This does not apply to the
exploratory cohort.

- Nephrotic syndrome

- Serum IgG < 600 mg/dL at screening.

- Chronic systemic immunosuppression, including glucocorticoids, within 16 weeks of
randomization

- Participation in another interventional clinical trial and receipt of another
investigational drug within 30 days prior to the administration of IMP or 5
half-lives from last investigational drug administration, whichever is longer.

- Chronic infectious disease, or acute infectious disease at time of screening.

- Type 1 diabetes, or poorly controlled Type 2 diabetes

- Uncontrolled hypertension

The protocol provides additional information about these and other inclusion and
exclusion criteria.