Safety and Efficacy of Gene Therapy of FHL Type 3 Caused by Mutations in the Human UNC13D Gene by Transplantation of a Single Dose of Autologous CD34+ Cells Transduced Ex Vivo with the UNC13D LV Vector Expressing the UNC13D CDNA

Phase 1

Not yet recruiting

Brief Summary: The investigators propose to replace HLA- partially compatible allogeneic Hematopoietic Stem Cell Transplantation (HSCT) for FHL type 3 patients, with autologous transplantation of immunoselected gene-modified CD34+ cells, combined with transduced autologous T-cell each time this is possible and also to propose this alternative treatment as salvage in case of failure of a previous allogeneic HSCT. This approach should avoid the severe immunological complications (failure to engraft, acute or chronic graft versus host disease (GVHD)) and conditioning toxicities such as severe Veno-Occlusive Disease (VOD). As the clinical manifestations of FHL type 3 patients are triggered by opportunistic viral infections (often EBV) and can be poorly controlled or only transiently controlled by the available drugs , providing the patient after the conditioning with immediately functional autologous cytotoxic T-cells could be key to maintain the control of the viral infection and hopefully its eradication awaiting for the hematopoietic reconstitution . This procedure should avoid any reactivation of the viral infection and thus improving the patients' overall survival and event-free survival while clearing the ongoing triggering infections.

Recruitment & Eligibility

Inclusion Criteria

Patient aged from 3 months up to 17 years old.
Patient with a FHL caused by mutation of the UNC13D gene.
Complete remission is defined by the normalization of clinical and laboratory parameters:
1. Resolution of fever
2. Resolution of splenomegaly or reduced and isolated splenomegaly.
3. Improvement of cytopenia: absolute neutrophil count > 500/µl AND platelets cout > 100 000/ µl (unsupported by transfusion)
4. Normalization of serum fibrinogen level (Fibrinogen ≥1.5g/l)
5. Resolution of hyperferritinemia (Ferritin level < 2000µg/l)
6. Normalization of T-cell activation
Patient eligible for an allogeneic HSCT in absence of an HLA geno-identical donor (at diagnostic or 6 months after failure of a previous HSCT (rejection or loss of the graft))
Parental, guardian's patient signed informed consent.
For patients of childbearing age : willing to use an effective method of contraception* during the trial and for at least 12 months post-infusion
Affiliation to Social Security

Exclusion Criteria

Active CNS encephalitis related to HLH
Existence of a matched -sibling donor
Unwillingness to return for follow-up during the 2 years study and lifelong for off study review.
HIV-1 or 2 or HTLV1 infections.
Patient on AME (state medical aid) (unless exemption from affiliation)
Pregnancy or breast feeding in a post-partum female
Diagnosis of significant psychiatric disorder of the subject that could seriously impeded the ability to participate in the study
Known allergies, hypersensitivity, or intolerance to any of busulfan, fludarabine, rituximab, G-CSF, plerixafor or excipients, or similar compounds
Unable to tolerate general anesthesia and/or apheresis
Participation in another clinical study with an investigational drug within 30 days of inclusion.
Uncontrolled HLH manifestation

Arm && Interventions

Group	Intervention	Description
MUNC	MUNC-CD34	-
MUNC	MUNC-T3	-

Primary Outcome Measures

Name	Time	Method
Incidence of Transplantation Related Mortality (TRM)	up to 6 months post treatment
Frequency and severity of clinical AEs and laboratory parameters	throughout the whole period of the research, up to 60 months	Adverse event will be measured using CTCAE
Incidence of clinically detectable malignancy and/or abnormal clonal dominance assessed as related to study treatment	At 12 months post treatment	Bone marrow analysis and VISA
Detection of Replication -Competent Lentivirus (RCL)	at 3, 6 and 12 months post treatment, then yearly up to 60 months

Secondary Outcome Measures

Name	Time	Method
Neutrophil and platelet recovery	throughout the whole period of the research, up to 60 months	ANC\> 500/µl, Platelets \> 20.000/µl on two consecutive days without transfusion
Quantification of the transgene copy number (VCN) on drug substance at time of cryopreservation, on PBMC, sorted T-CD3+ and sorted NK cells	at 1, 2, 3, 6, 9, 12, 18 and 24 months post treatment
Quantification of the UNC13D RNA on PBMC	at 1, 2, 3, 6, 9, 12, 18 and 24 post treatment	by Q-PCR
Quantification of Munc13.4 protein level in the drug substance and on peripheral blood mononuclear cells and on sorted CD3+ and CD56+ cells in function of their number	at 6, 12 and 24 months post treatment	by western blot
Determination of the total number of T-cells and distribution of different subpopulations	at 1, 2, 3, 6, 12, 18 and 24 months post treatment	Naïve and memory CD4+ and CD8+ T cells will be evaluated using CCR7/CD45RA/RO markers, and the quantification of activation marker will be performed by the expression of DR+. by flow cytometry
Correction of degranulation function in T-CD3	at 6 months and 24 months post treatment
Integration site analyse study	at 24 months post treatment
Needs of PICU support	up to 24 months post treatment
Endothelial complications	up to 24 months post treatment
Infectious diseases	up to 24 months post treatment
Estimate of the cost of the complete procedure, from mobilisation to transplant	up to 24 months post treatment
stimate of the 24 months total cost	up to 24 months post treatment