Sparsentan in Posttransplant Immunoglobulin A Nephropathy or Focal Segmental Glomerulosclerosis

Inclusion Criteria:

• Willing and capable of giving signed informed consent which includes compliance withthe requirements and restrictions listed in the ICF and in the protocol.

• Male and female aged ≥18 years

• Participants with a kidney transplant with biopsy-proven IgAN or FSGS histologicalpattern in the graft.

• A period of ≥12 months since kidney transplantation.

• UPCR ≥0.5 g/g and eGFR (CKD-EPI creatinine-based formula ≥30 mL/min/1.73 m2.

• Participants who can become pregnant, must agree to the use of 1 highly reliablemethod of contraception from 7 days prior to the first dose of study interventionuntil 30 days after the last dose of study intervention.

• Systolic BP ≤160 mmHg and ≥100 mmHg, and diastolic BP ≤100 mmHg and ≥60 mmHg atscreening.

• For participants on an ACEI and/or ARB, and/or sodium glucose cotransporter-2 (SGLT2) inhibitor, the dosing regimen(s) is stable for ≥6 weeks prior to screening.

Exclusion Criteria:

• Participant has multiorgan transplants (with the exception of pancreas and cornealtransplants).

• Immunosuppressive therapy (IST) regimen for kidney transplant or other systemicchronic ISTs including enteric budesonide that is not stable for >6 weeks prior toDay 1. Exceptions include routine changes in the dose of CNIs to meet target level.

• <3 months after antirejection treatment and active rejection.

• Active bacterial, fungal or viral infection and/or active treatment of infectionincluding BK virus (BKV), cytomegalovirus (CMV), human immunodeficiency virus (HIV),Hepatitis B and C <3 months prior to and during the screening period.

• Current treatment for surgical complications.

• History of heart failure (New York Heart Association [NYHA] Class II-IV).

• Jaundice, hepatitis, or known hepatobiliary disease.

• Malignancy within the past 2 years with the exception of adequately treated basalcell carcinoma or non-metastatic squamous cell carcinoma of the skin, with noevidence or recurrence.

• History of alcohol or illicit drug use disorder (as defined in the Diagnostic andStatistical Manual of Mental Disorders, 5th Edition).

• History of serious side effects or allergic response to any angiotensin IIantagonist or ERA.

• Participant requires any of the prohibited concomitant medications.

• Treatment with sparsentan <12 weeks prior to screening.

• Participant has participated in a study of another investigational product <28 daysprior to screening or plans to participate in such a study during the course of thisstudy.

• Hematocrit <27%, hemoglobin <90 g/L (9 g/dL), or potassium >5.5 mmol/L (5.5 mEq/L).

• The participant is pregnant, plans to become pregnant during the course of thestudy, or is breastfeeding.

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

• The participant, in the opinion of the Investigator, has a medical condition orabnormal clinically significant laboratory screening value not listed above that mayinterfere with the evaluation of sparsentan safety or activity.