Atrasentan in Patients With Proteinuric Glomerular Diseases

Inclusion Criteria:

   - Age 18 years and older for patients in the IgAN, FSGS, and Alport Syndrome cohorts

   - Age 18-70 years for patients in the DKD cohort

   - Receiving a maximally tolerated dose of RAS inhibitor therapy (ACEi or ARB) that has
   been stable for at least 12 weeks.

   - For patients enrolling in IgAN Cohort:

      1. Biopsy-proven IgA nephropathy

      2. UPCR between 0.5 to less than 1.0 g/g

      3. Screening eGFR ≥ 30 mL/min/1.73 m2

   - For patients enrolling in FSGS Cohort:

      1. Biopsy-proven FSGS or documented genetic mutation in a podocyte protein
      associated with FSGS

      2. UPCR > 1.0 g/g

      3. Screening eGFR ≥ 30 mL/min/1.73 m2

      4. Subjects receiving systemic corticosteroids or other immunosuppressants must be
      on a stable dose for at least 12 weeks.

      5. BMI ≤ 40 kg/m2

   - For patients enrolling in Alport syndrome Cohort:

      1. Diagnosis of Alport syndrome by genetic testing

      2. UPCR > 0.5 g/g

      3. Screening eGFR ≥ 30 mL/min/1.73 m2

   - For patients enrolling in DKD Cohort:

      1. Diagnosis of type 2 diabetes mellitus

      2. UACR ≥ 0.5 g/g

      3. Screening eGFR ≥ 45 mL/min/1.73 m2

      4. Receiving a stable dose of SGLT2 inhibitor for at least 12 weeks

   - Willing and able to provide informed consent and comply with all study requirements

Exclusion Criteria:

   - Current diagnosis of another cause of chronic kidney disease or another primary
   glomerulopathy.

   - History of kidney transplantation or other organ transplantation.

   - Except for FSGS patients, use of systemic immunosuppressant medications, such as
   steroids, for more than 2 weeks in the past 3 months.

   - Blood pressure above 150 mmHg systolic or 95 mmHg diastolic as evaluated by the
   Investigator.

   - History of heart failure or a previous hospital admission for fluid overload.

   - Clinically significant history of liver disease as assessed by the Investigator.

   - Hemoglobin below 9 g/dL as measured by the Investigator or blood transfusion for
   anemia within the past 3 months.

   - Clinical diagnosis of nephrotic syndrome

   - Malignancy within the past 5 years. Exception to the criteria include nonmelanoma skin
   cancer and curatively treated cervical carcinoma in situ.

   - For women, pregnant, breastfeeding, or intent to become pregnant during the study.

   - For men, intent to father a child or donate sperm during the study.

   - Recently received an investigational agent.

   - Clinically significant unstable or uncontrolled medical condition as assessed by the
   Investigator.