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Randomized, Double-Blind, Safety and Efficacy Study of RE-021 (Sparsentan) in Focal Segmental Glomerulosclerosis

Efficacy and Safety of Sparsentan (RE-021), a Dual Endothelin Receptor and Angiotensin Receptor Blocker, in Patients With Focal Segmental Glomerulosclerosis (FSGS): a Randomized, Double-Blind, Active-Control, Dose-Escalation Study

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01613118
Acronym
DUET
Enrollment
109
Registered
2012-06-06
Start date
2014-03-31
Completion date
2024-03-25
Last updated
2025-05-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Focal Segmental Glomerulosclerosis

Keywords

Primary FSGS, Nephrotic syndrome, Steroid Resistant

Brief summary

This study will investigate whether RE-021 (Sparsentan), a selective dual-acting receptor antagonist with affinity for endothelin (A type) and angiotensin II receptors (Type 1), is safe and effective in treating patients with focal segmental glomerulosclerosis (FSGS).

Detailed description

Focal segmental glomerulosclerosis (FSGS) is a rare glomerular disorder which results in frank proteinuria and in some patients progression to end-stage kidney disease (ESKD) over 5-10 years. Proteinuria reduction is widely regarded to be beneficial and is considered the primary goal of treatment in FSGS and slowing its progressive course (D'Agati, et. al, 2011). Patients are currently treated with angiotensin receptor blockers (ARB) and angiotensin converting inhibitors (ACEI) to lower proteinuria with steroids, calcineurin inhibitors, and other immunosuppressive agents reserved for patients with severe proteinuria and in particular with nephrotic syndrome. Despite these therapies, many patients have nephrotic range proteinuria and new therapeutic agents are needed. Endothelin receptor antagonists (ERA) have been shown to lower proteinuria in clinical trials of diabetic nephropathy and have been speculated to be effective in FSGS.

Interventions

DRUGRE-021 (Sparsentan)

Oral, once-daily

DRUGIrbesartan

Oral, once-daily

Sponsors

Travere Therapeutics, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
8 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

1. Biopsy-proven FSGS OR documentation of a genetic mutation in a podocyte protein associated with the disease. 2. Urine protein/creatinine ratio (Up/C) at or above 1.0 g/g. 3. Estimated glomerular filtration rate (eGFR) \>30. 4. Mean seated blood pressure (BP) \>100/60 mmHg and \<145/95 in patients \>/= 18 years of age. Mean seated BP for patients \<18 years of age should be \>90/60 mmHg and \<95th percentile for age, gender, and height. 5. If a patient is taking immunosuppressive medications (except for Rituximab or cyclophosphamide), the dose and/or levels must be stable for 1 month prior to randomization and the Investigator should not have plans to alter the regimen during the first 8 weeks of treatment, except to stabilize levels. Patients on Rituximab or cyclophosphamide will be eligible provided they have not been taking these medications for 3 months prior to randomization. 6. US Sites: Males or females 8 to 75 years of age willing and able to provide written informed consent and/or assent, with informed consent signed by patient or parent/legal guardian. 7. EU Sites: Males or females 18 to 75 years of age willing and able to provide written informed consent, with informed consent, signed by patient or legal guardian.

Exclusion criteria

1. Patients with FSGS secondary to another condition. 2. Patients with history of type 1 diabetes mellitus, uncontrolled type 2 diabetes mellitus (HBA1c\>8%), or non-fasting blood glucose \>180 mg/dL at screening. 3. Patients who have had any organ transplant. 4. Patients with a requirement for any of the medications indicated on the list of Excluded Medications, with the exception of ACE and ARBs. 5. Patients with a documented history of heart failure (NYHA Class II-IV), and / or previous hospitalization for heart failure or unexplained dyspnea, orthopnea, paroxysmal nocturnal dyspnea, ascites and peripheral edema. Patients with clinically significant cerebrovascular disease (transient ischemic attack or stroke) and/or coronary artery disease (hospitalization for myocardial infarction or unstable angina, new onset of angina with positive functional tests or coronary angiogram revealing stenosis, coronary revascularization procedure) within 6 months before screening. 6. Patients with clinically significant cardiac conduction defects, including second or third degree atrioventricular block, left bundle branch block, sick sinus syndrome, atrial fibrillation, atrial flutter, an accessory bypass tract, or any arrhythmia requiring medication. 7. Patients with jaundice, hepatitis, or known hepatobiliary disease (includes asymptomatic cholelithiasis); alanine aminotransferase and/or aspartate aminotransferase \>2 times the upper limit of normal at Screening. 8. Patients positive for human immunodeficiency virus (HIV), and markers indicating acute (positivity of at least one of the following: Hepatitis B surface antigen \[HBsAg\], Hepatitis B e antigen \[HBeAg\], Hepatitis B virus \[HBV\] DNA in blood or liver, Immunoglobulin M Hepatitis B core antibody) or chronic (HBsAg and/or HBeAg and/or Hepatitis B virus \[HBV\] DNA positivity) HBV infection, or hepatitis C virus (HCV) infection (reactive anti-HCV antibody and/or HCV RNA). Testing at screening is only required for patients \>/= 18 years of age. 9. History of malignancy other than adequately treated basal cell or squamous cell skin cancer within the past 5 years. 10. Patients with hemodynamically significant valvular disease. 11. Hematocrit (HCT) \<27 or hemoglobin (Hgb) \<9. 12. Potassium \>5.5 mEq/L. 13. Patients \>18 years of age with Estimated Glomerular Filtration Rate (eGFR) ≥60 ml mL/min who have N-terminal prohormone of brain natriuretic peptide (NT-proBNP) ≥200 pg/mL (57.8 pmol/L). For patients \>18 years of age with eGFR \<60 mL/min, the following parameters requiring echocardiography (ECHO) at screening should be used for exclusion: 1. NT-proBNP ≥300 pg/mL in patients \>18 years of age with eGFR 45 59.9 mL/min 2. NT-proBNP = 200-299 pg/mL in patients \>18 years of age with eGFR 45 59.9 mL/min, and abnormal ejection fraction (EF \<55) and/or diastolic dysfunction on ECHO 3. NT-proBNP ≥400 pg/mL in patients \>18 years of age with eGFR 30.0 44.9 mL/min 4. NT-proBNP = 200-399 pg/mL in patients \>18 years of age with eGFR 30.0 44.9 mL/min, and abnormal ejection fraction (EF \<55) and/or diastolic dysfunction on ECHO. 14. Patients \>/= 18 years of age with body mass index (BMI) \>40. Patients \<18 years of age with a BMI in the 99% percentile plus 5 units. 15. Patients who have abnormal clinical laboratory values at Screening, which are designated by the Principal Investigator as clinically significant. 16. Patients with a history of drug or alcohol abuse within the past two years. 17. Patients with a history of an allergic response to any angiotensin II antagonist or endothelin receptor antagonist. 18. Women who are pregnant or breastfeeding. 19. Women of child-bearing potential (WOCBP) who are unwilling or unable to use two reliable methods of contraception, with at least one being highly reliable (e.g. oral, implanted or injected contraceptive hormones or an intrauterine device) and one being a barrier method, in order to avoid pregnancy for the entire study period and for 90 days post study participation. WOCBP, defined as all women physiologically capable of becoming pregnant, includes any female who has experienced menarche and who has not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation or bilateral ovariectomy) or is not postmenopausal (defined as amenorrhea \>12 consecutive months and for women on hormone replacement therapy, only with documented plasma follicle stimulating hormone level greater than 35 mIU/mL). Women using oral, implanted or injected contraceptive hormones, an intrauterine device, barrier methods (diaphragm, condoms, spermicidal) to prevent pregnancy, practicing abstinence or where the partner is sterile (e.g. vasectomy) As well as postmenopausal women who have fertilized eggs implanted are also considered WOCBP. 20. Patients who have participated in another investigational drug study within 28 days prior to screening, or who will participate in another drug study during the course of this study. 21. Prior exposure to Sparsentan, dual acting receptor antagonist (DARA), or PS433540. 22. Patients who are unable to comply with the study procedures and assessments, including the ability swallow the study drug or control capsules.

Design outcomes

Primary

MeasureTime frameDescription
Percent Change in Urine Protein/Creatinine (Up/C)8 weeksPrimary efficacy objective is to determine the change in UP/C in FSGS patients receiving RE-021 (Sparsentan) from baseline to 8 weeks over a range of dose levels compared to treatment with irbesartan as active control.

Secondary

MeasureTime frameDescription
Percentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)8 weeksThe secondary efficacy endpoint is the proportion of FSGS patients achieving FPRE (experiencing a UP/C ratio ≤1.5 g/g and \>40% reduction from baseline in Up/C) at Week 8 over a range of dose levels compared to treatment with irbesartan as active control.

Countries

Czechia, Italy, United States

Participant flow

Pre-assignment details

For the Double-Blind (DB) period, patients were screened to confirm eligibility and underwent 2-wk washout period to discontinue ARBs or ACEIs if necessary. Subjects who completed DB period were evaluated to determine eligibility for the Open-Label Extension (OLE) period (up to 496 additional weeks), those treated with irbesartan were offered sparsentan in the OLE period. Dose changes were permitted during the OLE so all subjects enrolled in OLE are included in RE-021(Sparsentan)-OLE Period arm.

Participants by arm

ArmCount
RE-021 (Sparsentan) 200 mg - Double-Blind Period
RE-021 (Sparsentan) administered as a single oral morning dose. In this ARM the RE-021 (Sparsentan) dose was 200mg. Patients at \</= 50kg received half the RE-021 (Sparsentan) dose for the 8 week duration. RE-021 (Sparsentan): Oral, once-daily
13
RE-021 (Sparsentan) 400 mg - Double-Blind Period
RE-021 (Sparsentan) administered as a single oral morning dose. In this ARM the RE-021 (Sparsentan) dose was 400mg. Patients at \</= 50kg received half the RE-021 (Sparsentan) dose for the 8 week duration. RE-021 (Sparsentan): Oral, once-daily
26
RE-021 (Sparsentan) 800 mg - Double-Blind Period
RE-021 (Sparsentan) administered as a single oral morning dose. In this ARM the RE-021 (Sparsentan) dose was 800mg. Patients at \</= 50kg received half of the RE-021 (Sparsentan) dose for the 8 week duration. RE-021 (Sparsentan): Oral, once-daily
34
Irbesartan 300 mg - Double-Blind Period
The control irbesartan was administered as a single oral dose of 150mg for the first week before being escalated to 300mg for the remaining 7 weeks. Patients at \</= 50kg received 150mg irbesartan for the 8 week duration. Irbesartan: Oral, once-daily
36
Total109

Baseline characteristics

CharacteristicRE-021 (Sparsentan) 200 mg - Double-Blind PeriodRE-021 (Sparsentan) 400 mg - Double-Blind PeriodRE-021 (Sparsentan) 800 mg - Double-Blind PeriodIrbesartan 300 mg - Double-Blind PeriodTotal
Age, Continuous42.8 years
STANDARD_DEVIATION 14.36
38.3 years
STANDARD_DEVIATION 16.78
35.9 years
STANDARD_DEVIATION 17.68
34.1 years
STANDARD_DEVIATION 15.96
36.7 years
STANDARD_DEVIATION 16.54
Sex: Female, Male
Female
6 Participants9 Participants17 Participants17 Participants49 Participants
Sex: Female, Male
Male
7 Participants17 Participants17 Participants19 Participants60 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
deaths
Total, all-cause mortality
0 / 130 / 260 / 340 / 360 / 108
other
Total, other adverse events
11 / 1317 / 2627 / 3426 / 36104 / 108
serious
Total, serious adverse events
0 / 130 / 262 / 341 / 3648 / 108

Outcome results

Primary

Percent Change in Urine Protein/Creatinine (Up/C)

Primary efficacy objective is to determine the change in UP/C in FSGS patients receiving RE-021 (Sparsentan) from baseline to 8 weeks over a range of dose levels compared to treatment with irbesartan as active control.

Time frame: 8 weeks

Population: Efficacy evaluable set

ArmMeasureValue (GEOMETRIC_LEAST_SQUARES_MEAN)
RE-021 (Sparsentan) 200, 400, 800 mg PooledPercent Change in Urine Protein/Creatinine (Up/C)-44.8 percent change
Irbesartan 300 mg PooledPercent Change in Urine Protein/Creatinine (Up/C)-18.5 percent change
RE-021 (Sparsentan) 400 and 800 mg PooledPercent Change in Urine Protein/Creatinine (Up/C)-47.4 percent change
RE-021 (Sparsentan) 200mgPercent Change in Urine Protein/Creatinine (Up/C)-33.1 percent change
RE-021 (Sparsentan) 400mgPercent Change in Urine Protein/Creatinine (Up/C)-52.7 percent change
RE-021 (Sparsentan) 800mgPercent Change in Urine Protein/Creatinine (Up/C)-41.3 percent change
Secondary

Percentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)

The secondary efficacy endpoint is the proportion of FSGS patients achieving FPRE (experiencing a UP/C ratio ≤1.5 g/g and \>40% reduction from baseline in Up/C) at Week 8 over a range of dose levels compared to treatment with irbesartan as active control.

Time frame: 8 weeks

Population: Efficacy evaluable set. The sparsentan arms were compared to irbesartan in several different combinations that were defined in the study's Statistical Analysis Plan.

ArmMeasureValue (NUMBER)
RE-021 (Sparsentan) 200, 400, 800 mg PooledPercentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)28.13 percentage of patients
Irbesartan 300 mg PooledPercentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)9.38 percentage of patients
RE-021 (Sparsentan) 400 and 800 mg PooledPercentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)31.37 percentage of patients
RE-021 (Sparsentan) 200mgPercentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)15.38 percentage of patients
RE-021 (Sparsentan) 400mgPercentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)38.10 percentage of patients
RE-021 (Sparsentan) 800mgPercentage of Patients Achieving FSGS Partial Remission Endpoint (FPRE)26.67 percentage of patients

Source: ClinicalTrials.gov · Data processed: Mar 2, 2026