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

This clinical trial will investigate the efficacy and safety of TARPEYO® treatment extended for an additional 15 months in adult IgAN participants who have completed their initial, single 9-month TARPEYO® 16 mg QD commercial treatment regimen. Participants with residual proteinuria will be eligible for enrollment. The Treatment Period will consist of a 6-month Treatment Period with TARPEYO® 16 mg QD, followed by a 9-month Treatment Period with TARPEYO® 8 mg QD. This will be followed by a 3-month Follow-up Period, which includes the first 2 weeks of Tapering Period with TARPEYO® 4 mg QD.

The overall aim of the extended treatment is to improve and maintain the treatment effect with reduced proteinuria and protection of kidney function over a total of 2 years of TARPEYO® treatment.

Inclusion criteria

• Diagnosed IgAN with biopsy verification
• Female or male participants ≥18 years of age
• Completion of a single, initial 9 months of treatment with TARPEYO® 16 mg QD at the Baseline visit
• Access to retrospective local laboratory assessment data on UPCR and serum creatinine. Available retrospective data should include at least 1 assessment timepoint within 3 months prior to the first dose of TARPEYO® commercial treatment.
• On stable treatment with renin-angiotensin system (RAS) inhibitor therapy or sparsentan 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.
• If on current treatment with sodium-glucose cotransporter-2 (SGLT2) inhibitor, the treatment 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

• Participants who have been treated with systemic immunosuppressive medications including glucocorticosteroids (GCS) other than TARPEYO® during the TARPEYO® commercial treatment period. Topical or inhalation products containing GCS or immunosuppressants are allowed.
• Presence of other glomerulopathies (e.g., C3 glomerulopathy, diabetes nephropathy and/or hypertensive nephropathy).
• Presence of nephrotic syndrome (i.e., proteinuria >3.5 g per day and serum albumin <3.0 g/dL, with or without edema).
• Presence of medical condition excluding continued TARPEYO® treatment, as assessed by the Investigator.
• On current or planned dialysis.
• Undergone kidney transplant.
• Poorly controlled diabetes mellitus or hypertension, as assessed by the Investigator.
• Participants with known osteoporosis in the medium- or high-risk category according to the 2010 American College of Rheumatology recommendations.
• Any medical or social circumstance making trial participation and/or TARPEYO® treatment unsuitable, as assessed by the Investigator.
• Participants with clinically significant infections that put the participant at risk, at the discretion of the Investigator.
• Participants unwilling or unable to meet the requirements of the protocol.
• Intake of another investigational drug during trial, or during the preceding 9-monthcommercial TARPEYO® treatment period.
• Females who are pregnant, breastfeeding, or plan to become pregnant in the trial period.
• Participants taking potent inhibitors of cytochrome P450 (CYP) 3A4