Efficacy and Safety of Extended TARPEYO® Treatment Beyond 9 Months in Adult Patients With Primary IgA Nephropathy

Inclusion Criteria:

1. Diagnosed IgAN with biopsy verification

2. Female or male participants ≥18 years of age

3. Completion of 9 months of treatment with TARPEYO® 16 mg QD at the Baseline visit

4. Access to retrospective local laboratory assessment data on UPCR and serumcreatinine. Available retrospective data should include at least 1 assessment timepoint within 3months prior to the first dose of TARPEYO® commercial treatment

5. Proteinuria at Screening based on 2 consecutive measurements (24-hour urinecollection) after informed consent, separated by at least 1 week and calculated bythe central laboratory. Both samples of the same parameter must show either of the following:

• Proteinuria ≥0.5 g per day (≥500 mg per day) in 2 consecutive measurements, or

• UPCR ≥0.3 g/gram in 2 consecutive measurements

6. On stable treatment with renin-angiotensin system (RAS) inhibitor therapy for atleast 8 weeks prior to the Baseline visit. A stable dose is defined as a dose within 25% of the dose at Baseline

7. If on current treatment with sodium-glucose cotransporter-2 (SGLT2) inhibitor, thetreatment should have been stable for at least 8 weeks prior to the Baseline visit.A stable dose is defined as a dose within 25% of the dose at Baseline

Exclusion Criteria:

1. Participants who have been treated with systemic immunosuppressive medicationsincluding glucocorticosteroids (GCS) other than TARPEYO® during the TARPEYO®commercial treatment period. Topical or inhalation products containing GCS orimmunosuppressants are allowed

2. Presence of other glomerulopathies (e.g., C3 glomerulopathy and/or diabetesnephropathy)

3. Presence of nephrotic syndrome (i.e., proteinuria >3.5 g per day and serum albumin <3.0 g/dL, with or without edema)

4. Presence of medical condition excluding continued TARPEYO® treatment, as assessed bythe Investigator

5. On current or planned dialysis.

6. Undergone kidney transplant.

7. Poorly controlled diabetes mellitus or hypertension, as assessed by theInvestigator.

8. Participants with known osteoporosis in the medium- or high-risk category accordingto the 2010 American College of Rheumatology recommendations.

9. Any medical or social circumstance making trial participation and/or TARPEYO®treatment unsuitable, as assessed by the Investigator.

10. Participants with clinically significant infections that put the participant atrisk, at the discretion of the Investigator.

11. Participants unwilling or unable to meet the requirements of the protocol.

12. Intake of another investigational drug during trial, or during the preceding 9-monthcommercial TARPEYO® treatment period.

13. Females who are pregnant, breastfeeding, or plan to become pregnant in the trialperiod.

14. Participants taking potent inhibitors of cytochrome P450 (CYP) 3A4