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.