This multicenter, prospective, single-arm clinical study will evaluate the probable benefit and safety of the LIPOSORBER® LA-15 System for the treatment of adult patients with nephrotic syndrome associated with primary focal segmental glomerulosclerosis, when the standard treatment options, including corticosteroid and/or calcineurin inhibitors treatments, have been unsuccessful or not well tolerated, and the patient has a GFR ≥ 45 ml/min/1.73m2, or the patient has post-renal transplant recurrence. Treatment for FSGS is considered unsuccessful if the patient is unresponsive to standard therapy (e.g., at least 8 weeks of corticosteroids) and fails to achieve complete or partial remission. A standard treatment is considered not well tolerated if the patient experiences severe side effects without providing an acceptable level of clinical benefit.

This study will enroll up to 35 adult patients at 3-10 clinical sites. The duration of the treatment phase of the study will take approximately 9 weeks for a total of 12 apheresis treatments with the LIPOSORBER® LA-15 System; the treatments will be given twice weekly for 3 weeks followed by once weekly for 6 weeks. Patients will undergo follow-up at 1, 3, 6, 12, and 24 months after the final apheresis treatment.

This study is conducted as a Post Approval Study imposed by Humanitarian Device Exemption (HDE) order to confirm the safety and efficacy of the LIPOSORBER® LA-15 System in the treatment of drug-resistant primary FSGS and post Transplant recurrence.

Inclusion Criteria:

A patient is deemed suitable for inclusion in the study if the patient has nephrotic syndrome associated with primary FSGS when:

• Standard treatment options, including corticosteroid and/or calcineurin inhibitors, are unsuccessful or not well tolerated and the patient's glomerular filtration rate (GFR) ≥ 45 ml/min/1.73 m2.

or

• The patient is post renal transplantation.

Exclusion Criteria:

General Exclusion Criteria

1. Patient is greater than 75 years of age at the start of the treatment period or less than 22
2. The patient is unwilling or unable to sign and date the informed consent
3. Pregnant, lactating, or planning to become pregnant prior to completing the study (Note: The safety of the use of LIPOSORBER® in pregnant women has not been studied. There may be unknown risks to an embryo/fetus. Sexually active women of childbearing potential should avoid pregnancy during the use of the LIPOSORBER device and throughout the study duration.)
4. Unable or unwilling to comply with the follow-up schedule
5. Simultaneously participating in another investigational drug or device study
6. Body weight < 15 kg (33.1 lbs)

Medical Exclusion Criteria

1. Currently being administered ACE inhibitors that cannot be withheld for at least 24 hours prior to each apheresis treatment (Note: The time period to withhold ACE inhibitors should be prolonged, if determined by the treating physician, considering each individual's renal function and the biological half-life of the ACE-inhibitor currently in use.)
2. Currently being administered antihypertensive drugs other than ACE inhibitors (e.g., ARBs) that cannot be withheld on the day of apheresis until after the procedure
3. Medical condition or disorder that would limit life expectancy to less than the primary clinical study endpoint or that may cause noncompliance with the study plan or confound the data analysis
4. Hypersensitivity to dextran sulfate, heparin, or ethylene oxide
5. Adequate anticoagulation cannot be achieved due to severe hemophilia, severe hemorrhage diathesis, severe gastrointestinal ulcers, or are recipients of vitamin K antagonist medications
6. Extracorporeal circulation therapy with LIPOSORBER® LA-15 System cannot be tolerated due to severe cardiac insufficiency, acute myocardial infarction, severe cardiac arrhythmia, acute apoplexy, severe uncontrollable hypertension, or severe uncontrollable hypotension Note: Severe uncontrollable hypotension/hypertension indicates the cases with systolic and/or diastolic blood pressure ≤ 5th percentile for age, gender, and height.
7. Cardiac impairments such as uncontrolled arrhythmia, unstable angina, decompensated congestive heart failure, or valvular disease
8. Functional thyroid disease or liver abnormalities
9. Unresolved systemic or local infection that could affect the clinical study outcomes