Sparsentan (Filspari) is an endothelin and angiotensin II receptor antagonist indicated to slow kidney function decline in adults with primary immunoglobulin A nephropathy (IgAN) who are at risk for disease progression and indicated to reduce proteinuria in adult and pediatric patients with focal segmental glomerulosclerosis (FSGS) without nephrotic syndrome.
Read on to learn more about Filspari, including its boxed warning contents, dosage and administration information, and more.
Medication Overview:
- Brand Name: Filspari
- Generic Name: sparsentan
- Indicated to: To slow kidney function decline in adults with primary IgAN who are at risk for disease progression; To reduce proteinuria in adult and pediatric patients aged 8 years and older with FSGS without nephrotic syndrome.
- Company: Travere Therapeutics
- Initial FDA Approval: February 2023
| Indication | Age | Date of Inital Approval |
|---|---|---|
| To reduce proteinuria in adult and pediatric patients aged 8 years and older with focal segmental glomerulosclerosis (FSGS) without nephrotic syndrome. | Adults and pediatric patients 8 and older | April 2026 |
| To slow kidney function decline in adults with primary immunoglobulin A nephropathy (IgAN) who are at risk for disease progression. | Adults | February 2023 |
Boxed Warning:
- Hepatotoxicity and Embryo-Fetal Toxicity
See full prescribing information for complete boxed warning.
- Filspari is only available through a restricted distribution program called the Filspari Risk Evaluation and Mitigation Strategies (REMS) because of the risk of hepatotoxicity.
- Some endothelin receptor antagonists have caused elevations of aminotransferases, hepatotoxicity, and liver failure.
- Measure liver aminotransferases and total bilirubin prior to initiation of treatment and ALT and AST every 3 months during treatment.
- Interrupt treatment and closely monitor patients developing aminotransferase elevations more than 3-times Upper Limit of Normal (ULN).
- Based on animal data, Filspari may cause fetal harm if used during pregnancy and is contraindicated in pregnancy.
- For patients who can become pregnant, exclude pregnancy prior to the initiation of treatment with Filspari.
- Use effective contraception prior to initiation of treatment, during treatment, and for two weeks after stopping Filspari.
- When pregnancy is detected, discontinue Filspari as soon as possible.
Warnings and Precautions:
- Hypotension
- Acute Kidney Injury
- Hyperkalemia
- Fluid Retention
Dosage and Administration:
- Prior to initiating treatment with Filspari, discontinue use of renin- angiotensin-aldosterone system (RAAS) inhibitors and endothelin receptor antagonists (ERAs).
- IgAN (Adult Patients): Initiate treatment with FILSPARI at 200 mg orally once daily. After 14 days, increase to 400 mg once daily, as tolerated.
- FSGS (Adult and Pediatric Patients 8 years and older):
- Greater than 50 kg: Initiate treatment with Filspari at 400 mg orally once daily. After 14 days, increase to 800 mg once daily, as tolerated.
- 50 kg and less: Initiate treatment with Filspari at 200 mg orally once daily. After 14 days, increase to 400 mg once daily, as tolerated.
- When resuming Filspari after interruption, consider re-titration.
- Instruct patients to swallow tablets whole with water prior to the morning or evening meal.
- For patients who are unable to swallow whole tablets, Filspari may be crushed and mixed with water immediately before administration.
Contraindications:
- Pregnancy.
- Concomitant use with angiotensin receptor blockers (ARBs), ERAs, or aliskiren.
Drug Interactions:
- Strong CYP3A inhibitors: Avoid concomitant use. Increased sparsentan exposure.
- Moderate CYP3A inhibitors: Monitor adverse reactions. Increased sparsentan exposure.
- Strong CYP3A inducers: Avoid concomitant use. Decreased sparsentan exposure.
- Non-steroidal anti-inflammatory drugs (NSAIDs) including selective cyclooxygenase (COX-2) inhibitors: Monitor for signs of worsening renal function. Increased risk of kidney injury.
- CYP2B6, 2C9, and 2C19 substrates: Monitor for substrate efficacy. Decreased exposure of these substrates.
- P-gp substrates: Monitor for adverse reactions of P-gp substrates with narrow therapeutic indices. Increased exposure to substrates.
- Agents Increasing Serum Potassium: Increased risk of hyperkalemia, monitor serum potassium frequently.
Adverse Reactions:
Most common adverse reactions in patients with IgAN (≥5%) are hyperkalemia, hypotension (including orthostatic hypotension), peripheral edema, dizziness, anemia, and acute kidney injury.
Most common adverse reactions in patients with FSGS (≥5%) are peripheral edema, hypotension (including orthostatic hypotension), hyperkalemia, dizziness, and anemia.
To report suspected adverse reactions, contact Travere Therapeutics at 1-877-659-5518 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Examples of Sparsentan in Guidelines
- Management of Immunoglobulin A Nephropathy (IgAN) and Immunoglobulin A Vasculitis (IgAV)
- Kidney Disease Improving Global Outcomes (KDIGO)
- September 2025
- “We suggest that patients who are at risk of progressive loss of kidney function with IgAN be treated with sparsentan.”
Please note: This article is current as of August 14, 2026. Consult our clinical guidelines library or drug information tool to ensure you always have the most up-to-date information.
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