IVIG in the Treatment of Autoimmune Small Fiber Neuropathy With TS-HDS, FGFR-3, or Plexin D1 Antibodies

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.

NCT Number	NCT04153422
Lead Sponsor	Endeavor Health Collaborators: Octapharma USA, Inc.
Conditions	Small Fiber Neuropathy, Autoimmune Small Fiber Neuropathy, Inflammatory Polyneuropathy, Immune-Mediated Neuropathy
Enrollment	20 participants
Start Date	2023-12-15
Primary Completion	2027-08-27 (estimated)
Study Completion	2028-02-28 (estimated)
Updated on ClinicalTrials.gov	2026-01-09