Safety and Efficacy Study of Transplantation of Autologous CD34+ Cells Transduced With the G2ARTE Lentiviral Vector Expressing the DCLRE1C cDNA in Artemis (DCLRE1C) Deficient Severe Combined Immunodeficiency Patients (ARTEGENE)

A Phase 1/2 Open Label Non Randomized Study, Multicentric, Single Arm Evaluating the Safety and Efficacy of Gene Therapy of the Severe Combined Immunodeficiency (SCID) Caused by Mutations in the Human DCLRE1C Gene (Artemis) by Transplantation of a Single Dose of Autologous CD34+ Cells Transduced ex Vivo With the G2ARTE Lentiviral Vector Expressing the DCLRE1C cDNA

The purpose of this study is to evaluate the Safety and Efficacy of Gene Therapy of the severe combined immunodeficiency (SCID) caused by mutations in the human DCLRE1C gene (Artemis) by transplantation of a single dose of autologous CD34+ cells transduced ex vivo with the G2ARTE lentiviral vector expressing the DCLRE1C cDNA.

Inclusion Criteria:

• Patient to 47 months
• SCID patients with confirmed biallelic mutations in the Artemis (DCLRE1C) gene even in the case of leaky forms characterised by a residual activity
• Absence of an HLA genoidentical donor or without rapidly available HLA-compatible unrelated donor (within six weeks of diagnosis)
• The patient can be treated by gene therapy without delay in case of active life threatening infections compromising the short-term prognosis and for which the delay in finding a phenoidentical donor is incompatible with the patient's condition of health. Active life threatening infections are defined as: viral respiratory infection, CMV infection, adenovirus infection, disseminated BCGitis or other infections grade ≥ 4 according to CTCAE scale
• Beneficiary of a social security scheme
• Parental, guardian's patient signed informed consent.

Exclusion Criteria

• Unwillingness to return for follow-up during the first 2 years study and the long term follow-up
• HIV-1 or 2 or HTLV1 infections
• Hypersensitivity to G-CSF, busulfan or Fludarabine
• Unable to tolerate general anesthesia and/or marrow harvest or peripheral blood stem cell collection (apheresis) or insertion of central venous catheter.