NCT04153422 · Endeavor Health
IVIG in the Treatment of Autoimmune Small Fiber Neuropathy With TS-HDS, FGFR-3, or Plexin D1 Antibodies
What this study is about
This study will enroll patients with small fiber neuropathy (SFN). The study will look at an given through a vein (IV) immunoglobulin (IVIG) called Panzyga. Panzyga is approved by the FDA as a therapy for Primary humoral immunodeficiency (PI) in patients 2 years of age and older; Chronic immune thrombocytopenia (ITP) in adults and Chronic inflammatory demyelinating polyneuropathy (CIDP) in adults.
View original scientific description
This study will enroll patients with small fiber neuropathy (SFN). The study will look at an intravenous immunoglobulin (IVIG) called Panzyga. Panzyga is approved by the FDA as a therapy for Primary humoral immunodeficiency (PI) in patients 2 years of age and older; Chronic immune thrombocytopenia (ITP) in adults and Chronic inflammatory demyelinating polyneuropathy (CIDP) in adults. It has not been approved by the FDA for use in SFN. There is mounting evidence that Intravenous Immunoglobulin (IVIG) can cause pain reduction and improve objective nerve fiber densities on skin biopsies in great numbers in SFN patients. The primary outcome is quantified improvement in intraepidermal nerve fiber density (IENFD) on repeat skin punch biopsy after 6 months of IVIG treatment.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Patients ≥ age 18
- Patient with clinical and biopsy evidence of pure small fiber neuropathy (with or without dysautonomia) as evidenced by reduced IENFD on skin biopsy using PGP 9.5 as the immunostain. Biopsy must have been performed within 12 months of study enrollment. If biopsies were not done at CRL, they will be repeated and done at 3 sites (upper and lower thigh, lower calf), to have consistent and equivalent biopsy data with the follow up biopsy done after 6 mos of treatment
- Patients must have elevated and/or abnormal titers of autoantibodies to TS-HDS-IgM, FGFR3-IgG, or Plexin-D1 measured by the Washington University Neuromuscular Laboratory (St Louis) within 12 mos of enrollment
- Patients must have a baseline pain score on a visual analogue scale (VAS) of Greater or equal to 4/10
- Patients must have a baseline Utah Early Neuropathy Scale (UENS) score of Greater or equal to 4/10
- Small Fiber Neuropathy Screening List (SFNSL) score of 11/84 or greater
- Non-pregnant, non-lactating female. Females of reproductive potential must use 2 forms of contraception or continuously abstain from heterosexual sex during treatment
Exclusion criteria
- Any other known cause for small fiber neuropathy other than the presence of the elevated titers of TS-HDS-IgM, FGFR3-IgG, or Plexin-D1 autoantibodies
- Patients with generalized, severe musculoskeletal conditions other than SFN that prevent a sufficient assessment of the patient by the physician
- Electromyography/nerve conduction study (EMG/NCS) evidence of large fiber polyneuropathy, to be confirmed by study PI
- Underlying severe heart, kidney, liver disease, or HIV infection, (Note: If there is no previous HIV test result documented within the last 5 years, a test may be performed in order to confirm eligibility)
- Patients with a history of deep vein thrombosis within the last year prior to baseline visit or pulmonary embolism ever; patients with susceptibility to embolism or deep vein thrombosis
- Known significant IgA deficiency with antibodies to IgA
- History of hypersensitivity, anaphylaxis or severe systemic response to immuno-globulin, blood or plasma derived products, or any component of IVIG 10%
- Known blood hyperviscosity, or other hypercoagulable states
- Use of IgG products within six months prior to enrollment
- Patients with a history of drug or alcohol abuse within the past five years prior to enrollment
- Patients unable to understand or unwilling or unable to comply with the study protocol
Where
- Glenview, Illinois
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jan 9, 2026 · Source of record for eligibility and locations