Part 1 - A Clinical Trial in Patients With Frequently Relapsing and Steroid-Dependent Nephrotic Syndrome

Inclusion Criteria: * Adults ≥18 years of age * History of nephrotic syndrome, characterized by heavy proteinuria and hypoalbuminemia * Recent nephrotic relapse in the 6 months prior to screening * Estimated glomerular filtration rate (eGFR) of ≥45 during screening * Not pregnant, breastfeeding, or lactating and agree to use a highly effective method of acceptable contraceptive for the trial duration, if applicable Exclusion Criteria: * Subjects with collapsing FSGS focal segmental glomerulosclerosis (FSGS) * Known secondary cause of nephrotic syndrome (e.g., diabetic nephropathy, systemic lupus erythematous, sickle cell anemia, malignancy, drug-induced, malaria) * History of kidney transplantation or other solid organ transplantation * History of any unstable chronic diseases/conditions, clinically significant abnormalities, or findings, that in the opinion of the Investigator, could compromise subject safety or affect the conduct of the trial