The Immune Dysregulation Polyendocrinopathy Enteropathy X-linked Syndrome is a Primary Immunodeficiency Caused by Pathogenic Variants in Forkhead Box Protein 3

The purpose of this study is to evaluate the safety and efficacy of FOXP3-T4 (an autologous gene therapy) alone or in combination with low-dose IL-2 for the treatment of IPEX syndrome. The therapy involves the transplantation of autologous CD4+ T-cells transduced ex vivo with the LV-EF1a-FOXP3-LNGFR lentiviral vector. The study follows a staggered approach: the first two patients will receive FOXP3-T4 monotherapy. Subsequent patients will receive FOXP3-T4 followed if needed by low-dose IL-2 treatment consisting of a daily dose for 5 days, then weekly administrations for 3 months. The study aims to stabilize autoimmune manifestations and potentially cure the underlying disease, ultimately allowing for the discontinuation of ongoing immunosuppressive treatments.