Study Evaluating a Gene Therapy for IPEX Syndrome Through the Expression of FOXP3 on Deficient T Cells to Produce Tregs-like. (THERIPEX)

Inclusion Criteria:

• Male patients only
• Patients aged from 1 - 45 years of age (the first three patients will be aged between 10 - 45 years of age)
• Patient with IPEX syndrome caused by mutation of the FOXP3 gene
• Patients are eligible from the second line of treatment onward, even those under controlled disease
• Patient with recurrent IPEX symptoms, under immune suppressive medications
• Patient for whom HSCT is not feasible or when no suitable compatible donor is available
• Patients who have had prior allogeneic blood stem cell transplantation (HSCT) with engraftment failure defined as no intake of donor cells
• Patient or parental, guardian's patient signed informed consent
• Male participants of reproductive potential with a partner of childbearing potential (WOCBP): willing to use an effective method of contraception during the trial and for at least 12 months post-infusion
• Affiliation to a French or European social security scheme

Exclusion Criteria:

• Unwillingness to return for follow-up during the 2-year study and during the 15 years of long term follow up study.
• Patient with short life expectancy
• Patient on AME (state medical aid) (unless exemption from affiliation).
• Diagnosis of a significant psychiatric disorder of the patient that could seriously impede the ability to participate in the study.
• Eligible for an HLA matched sibling or matched unrelated donor blood stem cell transplant (HLA 10/10) and be willing to undergo transplant.
• Patients with uncontrolled or ongoing active infections.
• HIV-1 or 2 or HTLV-1 infections.
• Patients with severe IPEX clinical presentation needing a rapid allogeneic HSCT treatment within 3 months.
• Patients with known history of hypersensitivity to IL-2 or any component of the formulation (mannitol, sodium lauryl sulfate, monosodium phosphate dehydrate, disodium phosphate dehydrate, glucose.