A Study to Investigate Safety and Effect of Sparsentan in Combination With SGLT2 Inhibition in Participants With IgAN

Inclusion Criteria:

• Aged ≥18 years at the time of signing the informed consent.

• Biopsy-proven IgAN. The biopsy may have been performed at any time in the past.

• UA/C ≥0.3 g/g at screening

• An eGFR value of ≥25 mL/min/1.73m^2 at screening.

• On a stable dose of an SGLT2 inhibitor for at least 12 weeks prior to screening.

• On a stable dose of ACEI and/or ARB therapy for at least 12 weeks prior to screeningthat is:

• The participant's maximum tolerated dose (MTD), and

• at least one half of the maximum labeled dose (MLD)

• Systolic BP must be ≤160 mmHg, and diastolic BP must be ≤110 mmHg at screening.

• For participants receiving chronic low dose systemic corticosteroids (defined as ≤10mg/day prednisone or equivalent), or an enteric formulation of budesonide and/or amineralocorticoid receptor antagonist (MRA), the dosage must be stable for ≥12 weeksprior to screening.

Exclusion Criteria:

• IgAN secondary to another condition or immunoglobulin A (IgA) vasculitis.

• Undergone any organ transplant, with the exception of corneal transplants.

• Documented history of heart failure.

• Taking high dose (defined as >10 mg/day prednisone) or other any systemicimmunosuppressive medications within 12 weeks of prior to screening.

• Has clinically significant cerebrovascular disease (transient ischemic attack orstroke) and/or coronary artery disease (hospitalization for myocardial infarctionunstable angina, new onset of angina with positive functional tests, coronaryangiogram revealing stenosis, or a coronary revascularization procedure) within 3months prior to screening.

• Has jaundice, hepatitis, or known hepatobiliary disease (excluding asymptomaticcholelithiasis), or ALT and/or AST >2 times the ULN range at screening.

• Has a history of malignancy other than adequately treated basal cell or squamouscell skin cancer or cervical carcinoma within the past 2 years.

• Has a history of serious side effect or allergic response to any AngII antagonist,ERA or sparsentan, or has a hypersensitivity to any of the excipients in the studyintervention.

• Requires any of the prohibited concomitant medications.

• Treatment with sparsentan within 12 weeks prior to screening

• Has participated in a study of another investigational product within 28 days priorto screening or plans to participate in such a study during the course of thisstudy.

• Has a screening hematocrit value <27% (0.27 Volume/Volume) or hemoglobin value <9g/dL (90 g/L).

• Has a screening potassium value of >5.5 mEq/L (5.5 mmol/L).

• Is pregnant, plans to become pregnant during the course of the study, or isbreastfeeding.

• The participant, in the opinion of the Investigator, is unable to adhere to therequirements of the study, including the ability to swallow the study interventioncapsules whole.