A Study of the Efficacy and Safety of DMX-200 in Patients With FSGS Who Are Receiving an ARB

Eligibility Criteria

• 1. Patients must be 12 to 80 years old
• 2. A diagnosis of primary FSGS, genetic FSGS, or FSGS of undetermined cause. Confirmed by kidney biopsy or documentation of a genetic mutation in a podocyte protein associated with FSGS
• 3. Must be either receiving an ARB at the maximal tolerated dose or willing to transition
• 4. If taking corticosteroids, the dosage must be stable for ≥4 weeks prior to Screening and during Stablization
• 5. If taking aldosterone inhibitors, mineralocorticoid receptor antagonists, direct renin inhibitors, sodium-glucose co-transporter-2 (SGLT2) inhibitors, or endothelin receptor antagonists (ERAs, including dual antagonists), the dose and regimen must be stable for ≥12 weeks prior to Screening and during Stablization
• 6. Urine PCR \>1.5 g/g (\>169.5 mg/mmol) or 24-hour total protein \>1.5 g/day based on 24-hour urine collection during Screening.
• 7. Estimated GFR ≥25 mL/min/1.73 m2 at Screening
• 8. Seated blood pressure ≤160/100 mm Hg (mean of 3 values) (patients ≥18 years of age) or between the 5th and 95th percentile for age, sex, and height 29 (patients \<18 years of age) at Screening.
• 9. Body weight ≥35 kg (all patients) AND a BMI ≤40 kg/m2 (patients ≥18 years of age) or between the 5th and 98th percentile for age and sex (patients \<18 years of age) at Screening.
• 10. A female patient is eligible to participate if she is not pregnant or planning to become pregnant during the study, not breastfeeding, and at least one of the following conditions applies:
• 1. Is not of childbearing potential
• 2. If of childbearing potential and beginning at menarche, agrees to use a highly effective method of contraception consistently during the treatment period.
• 11. A male patient with a female partner of childbearing potential is eligible to participate if he agrees to use acceptable contraception
• 12. A patient or parent/legal guardian (as appropriate) who is capable of giving signed informed consent, and where required, the patient is capable of providing assent.
• 1. Has FSGS secondary to another condition.
• 2. History of type 1 diabetes mellitus, or uncontrolled type 2 diabetes mellitus (defined as glycated hemoglobin \[HbA1c\] \>8%)
• 3. History of lymphoma, leukemia, or any active malignancy within the past 2 years
• 4. Active clinically significant hepatobiliary disease.
• 5. Documented history of heart failure (New York Heart Association Class III/IV) or a major adverse cardiac event within 12 weeks prior to Screening.
• 6. Has a physical, medical, or psychological condition, that in the opinion of the Investigator, may interfere with the evaluation the study.
• 7. The patient has a history of alcohol or illicit drug use disorder within 1 year prior to Screening.
• 8. Had a prior organ transplant or stem cell transplant, with the exception of corneal transplant.
• 9. Positive screening assessment for viral hepatitis B surface antigen, or anti-hepatitis C virus antibody AND positive HCV RNA, or human immunodeficiency virus 1 and 2.
• 10. Serum potassium levels \>5.5 mmol/L at Screening.
• 11. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) \>2 × upper limit of normal (ULN) at Screening
• 12. Treatment with immunosuppressant biological drugs, calcineurin inhibitors, cyclophosphamide, azathioprine, or mycophenolate mofetil within 12 weeks prior to Screening.
• 13. History of serious side effects or allergic response to an angiotensin II antagonist or has a known sensitivity to any components in the Investigational Product.
• 14. Unable to swallow oral medication.
• 15. Prior participation in any Dimerix-sponsored DMX-200 clinical study.
• 16. Participation in a clinical study with an Investigational Product within 28 days or 5 half-lives (whichever is longer) prior to Screening or plans to participate in another study during the course of this study.
• 17. Are study site personnel directly affiliated with this study and their immediate families.