Study of the Safety and Efficacy of OMS721 in Patients With Immunoglobulin A (IgA) Nephropathy

Inclusion Criteria:

• Age 18 years or older at the onset of Screening
• Biopsy confirmed diagnosis of IgAN within 8 years prior to Screening
• Proteinuria of > 1 g/day within 6 months prior to Screening or uPCR > 0.75 by spoturine at Screening
• Mean of two proteinuria measurements > 1 g/day at baseline
• Estimated glomerular filtration rate of ≥ 30 mL/min/1.73 m² at Screening and baseline

Exclusion Criteria:

• Treatment with immunosuppressants (e.g., azathioprine or cyclophosphamide), orcytotoxic drugs, for IgA within 8 weeks prior to Screening. Treatment withimmunosuppressants or cytotoxic drugs for IgAN is not allowed during the Run-InPeriod. Treatment with immunosuppressants are allowed if such treatment is forindications other than IgAN.
• Treatment with eculizumab within 8 weeks prior to Screening. Treatment with eculizumabis not allowed during the Run-In Period.
• Treatment with systemic corticosteroids within 8 weeks prior to Screening. Treatmentwith systemic corticosteroids is not allowed during the Run-In Period.
• Uncontrolled BP, a systolic BP of > 150 mmHg and a diastolic BP of > 100 mmHg at restdespite the combination of two or more anti-hypertensives including ACEIs, ARBs, ordirect renin inhibitors at Screening and baseline
• Female patients who are pregnant, breast feeding, or planning to become pregnant upthrough 12 weeks after the last dose of study drug, including possible retreatments.Males who are planning to father children up through 12 weeks after the last dose ofstudy drug, including possible retreatments
• Clinical or biological evidence of Type 1 diabetes mellitus (DM), or poorly controlledDM with hemoglobin A1c > 7.5 or with evidence of diabetic nephropathy on biopsy,systemic lupus erythematosus, IgA vasculitis (Henoch-Schonlein purpura), secondaryIgAN, or other renal disease during Screening and Run-In
• History of renal transplantation
• Have a known hypersensitivity to any constituent of the investigational product
• Rapidly progressive glomerulonephritis
• Significant abnormalities in clinical laboratory values
• History of human immunodeficiency virus (HIV), evidence of immune suppression, activeHCV infection (patients with positive anti-HCV antibody but a non-detected HCV RNA PCRcan enroll), HBV infection (patients with positive HBsAg are excluded. For patientswith isolated positive anti-HBc antibody, HBV DNA test by PCR must be non-detectableto enroll).
• Diagnosis of a malignancy except for adequately treated and cured basal or squamouscell skin cancer, curatively treated in situ disease, or other cancer from which thepatient has been disease-free for ≥ 5 years
• Have received any other investigational drug or device or experimental proceduresand/or treatments within 30 days of the Screening Visit (SV)
• Initiation or change in dosing of sodium glucose co-transporter 2 inhibitors (SGLT2i)during Screening and Run-In Periods. However, a stable dose regimen established atleast 8 weeks prior to screening is acceptable
• Treatment with Tarpeyo™ (budesonide) or other approved treatments for IgAN within 6months prior to screening. Treatment with Tarpeyo is not allowed during Screening andRun-In Periods
• Treatment with Kerendia® (finerenone) within 6 months prior to screening. Treatmentwith Kerendia is not allowed during Screening and Run-In Periods
• Initiation of treatment with Filspari™ (sparsentan), a dual Endothelin AngiotensinReceptor Antagonist (dEARA) or similar medication within three months prior toscreening. A stable dose initiated at minimum 3 months before screening is acceptableand will take the place of ACEi/ARB as background therapy