FDA approves Sparsentan for proteinuria reduction in IgAN

FILSPARI was granted accelerated approval in February 2023 based on the surrogate marker of proteinuria. Full approval is based on positive long-term confirmatory results from the PROTECT Study demonstrating that FILSPARI significantly slowed kidney function decline over two years compared to irbesartan.

“We know that most people living with IgAN are at risk of disease progression and are seeking a safe, effective and convenient treatment option that can help preserve their kidney function. Full approval now enables physicians to confidently prescribe FILSPARI more broadly as a once-daily, oral, non-immunosuppressive treatment, that can provide superior preservation of kidney function and replace current standard of care,” said Eric Dube, Ph.D., president and chief executive officer of Travere Therapeutics. “With KDIGO’s recent draft guidelines recommending FILSPARI as a foundational kidney-targeted therapy and lowering the targeted proteinuria level for all IgAN patients to under 0.5 g/day or 0.3 g/day – FILSPARI is well positioned to become foundational care for IgAN as the treatment landscape evolves. We are grateful to the patients, caregivers, clinical trial investigators, healthcare providers, and advocates who have worked alongside our team at Travere for so many years to help raise the bar on protecting and preserving kidney health for those living with rare kidney disease.”

FILSPARI is the only oral, once-daily, non-immunosuppressive medication that directly targets glomerular injury in the kidney by blocking two critical pathways of IgAN disease progression (endothelin-1 and angiotensin II).

The two-year efficacy data contained in the FDA-approved label is a modified intention to treat (ITT) analysis, and as preferred by the FDA, evaluates data from all patients regardless of treatment discontinuation. In the final analysis of the 404 randomized patients, FILSPARI significantly reduced the rate of decline in kidney function from baseline to Week 110 compared to irbesartan. In the ITT analysis included in the label, the mean eGFR slope from baseline to Week 110 was -3.0 mL/min/1.73 m2/year for FILSPARI and -4.2 mL/min/1.73 m2/year for irbesartan, corresponding to a statistically significant treatment effect of 1.2 mL/ min/1.73 m2/year (p=0.0168). The positive treatment effects on proteinuria compared to the active control irbesartan that were observed at Week 36 were durable out to the two-year measurement period. Additional results from the PROTECT Study demonstrated the benefit of FILSPARI on absolute eGFR accrued over time and by Week 110 resulted in a 3.8 mL/min/1.73 m2 difference in the mean change from baseline between FILSPARI and irbesartan.

Results from the PROTECT Study showed that FILSPARI was well tolerated with a clearly defined safety profile that has been consistent across all clinical trials conducted to date. Following engagement with the FDA, the Company expects to submit an sNDA for a potential modification to the liver-monitoring REMS.

“As a physician who has dedicated my career to treating patients with glomerular diseases, I believe the full approval of FILSPARI for IgAN provides us with a critically important tool for patient management,” said Brad Rovin, M.D., medical director at The Ohio State University Center for Clinical Research Management, director, Division of Nephrology, and steering committee member for the PROTECT Study. “This approval should facilitate patient access to a medication that targets injury directly in the kidney, reduces proteinuria, even to the point of complete remission in some patients, and is more effective than current standard-of-care treatment in preserving kidney function over time. This is a very exciting milestone in the evolution of treating IgAN.”

“Today’s full approval of FILSPARI brings new hope to the IgAN community, and I’m grateful for the progress that has been made in giving patients a new treatment option that can help protect their kidneys,” said Bonnie Schneider, executive director and co-founder of the IgA Nephropathy Foundation.

“The expanded indication and full approval of FILSPARI is welcome news for the rare kidney disease community,” said Josh Tarnoff, chief executive officer of NephCure. “We have waited a long time for a medicine to slow the irreversible kidney damage from IgAN and appreciate Travere’s leadership in championing new endpoints for IgAN that have spurred significant innovation for this rare kidney disease.”

Travere Therapeutics has a comprehensive patient support program, Travere TotalCare®, to enable a smooth experience for patients, their caregivers, and healthcare providers. This program provides services, assistance, and resources that can help patients understand IgAN, manage the insurance process, fill their prescriptions and initiate treatment.

About IgA Nephropathy

IgA nephropathy (IgAN), also called Berger's disease, is a rare progressive kidney disease characterized by the buildup of immunoglobulin A (IgA), a protein that helps the body fight infections, in the kidneys. The deposits of IgA cause a breakdown of the normal filtering mechanisms in the kidney, leading to blood in the urine (hematuria), protein in the urine (proteinuria) and a progressive loss of kidney function. Other symptoms of IgAN may include swelling (edema) and high blood pressure.

IgAN is the most common type of primary glomerulonephritis worldwide and a leading cause of kidney failure due to glomerular disease. IgAN is estimated to affect up to 150,000 people in the U.S. and is one of the most common glomerular diseases in Europe and Japan.

About the PROTECT Study

The PROTECT Study is one of the largest interventional studies to date in IgA nephropathy (IgAN) and the only Phase 3 head-to-head trial in this rare kidney disease. It is a global, randomized, multicenter, double-blind, parallel-arm, active-controlled clinical trial evaluating the safety and efficacy of 400 mg of FILSPARI (sparsentan), compared to 300 mg of irbesartan, in 404 patients ages 18 years and up with IgAN and persistent proteinuria despite receiving at least 50% of max label dose and maximally tolerated ACE or ARB therapy.

The primary efficacy endpoint for the interim analysis was the change from baseline in urine protein/creatinine ratio at Week 36. The key secondary efficacy endpoint for the final analysis was the rate of change in eGFR over a 110-week period following initiation of randomized therapy.

The trial met the pre-specified primary endpoint which showed that after 36 weeks patients receiving FILSPARI achieved a mean reduction in proteinuria from baseline of 49.8%, compared to a mean reduction in proteinuria from baseline of 15.1% for irbesartan-treated patients (p<0.0001).

The two-year efficacy data contained in the FDA-approved label is a modified intention to treat (ITT) analysis, and as preferred by the FDA, evaluates data from all patients regardless of treatment discontinuation. In the final analysis of 404 randomized patients, FILSPARI reduced the rate of decline in kidney function from baseline to Week 110 compared to irbesartan. The mean eGFR slope from baseline to Week 110 was -3.0 mL/min/1.73 m2/year for FILSPARI and -4.2 mL/min/1.73 m2/year for irbesartan, corresponding to a statistically significant treatment effect of 1.2 mL/ min/1.73 m2/year (p=0.0168).

Additional results from the PROTECT Study demonstrated the benefit of FILSPARI on absolute eGFR accrued over time and by Week 110 resulted in a 3.8 mL/min/1.73 m2 difference in the mean change from baseline between FILSPARI and irbesartan.

Patients who completed the PROTECT double-blind portion of the study on treatment were eligible to participate in the open-label extension of the trial.