Groupe Hospitalier University Ouest

Paris, France

Groupe Hospitalier University Ouest

Paris, France
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Hauer J.,University of Paris Descartes | Hauer J.,Heinrich Heine University Düsseldorf | Mullighan C.,St Jude Childrens Research Hospital | Morillon E.,University of Paris Descartes | And 16 more authors.
Blood | Year: 2011

In human B-acute lymphoblastic leukemia (B-ALL), RAG1-induced genomic alterations are important for disease progression. However, given that biallelic loss of the RAG1 locus is observed in a subset of cases, RAG1's role in the development of B-ALL remains unclear. We chose a p19Arf-/-Rag1 -/- mouse model to confirm the previously published results concerning the contribution ofCDKN2A(p19ARF/INK4a) and RAG1 copy number alterations in precursor B cells to the initiation and/or progression to B-acute lymphoblastic leukemia (B-ALL). In this murine model, we identified a new, Rag1-independent leukemia-nitiating mechanism originating from a Sca1 +CD19+ precursor cell population and showed that Notch1 expression accelerates the cells' self-renewal capacity in vitro. In human RAG1-deficient BM, a similar CD34+CD19+ population expressed p19ARF. These findings suggest that combined loss of p19Arf and Rag1 results in B-cell precursor leukemia in mice and may contribute to the progression of precursor B-ALL in humans. © 2011 by The American Society of Hematology.


Hacein-Bey-Abina S.,Groupe Hospitalier University Ouest | Hacein-Bey-Abina S.,CNRS Health Technology, Chemistry and Biology Unit | Hacein-Bey-Abina S.,University Paris - Sud | Pai S.-Y.,Dana-Farber Cancer Institute | And 73 more authors.
New England Journal of Medicine | Year: 2014

BACKGROUND In previous clinical trials involving children with X-linked severe combined immunodeficiency (SCID-X1), a Moloney murine leukemia virus-based γ-retrovirus vector expressing interleukin-2 receptor γ-chain (γc) complementary DNA successfully restored immunity in most patients but resulted in vector-induced leukemia through enhancermediated mutagenesis in 25% of patients. We assessed the efficacy and safety of a self-inactivating retrovirus for the treatment of SCID-X1.METHODS We enrolled nine boys with SCID-X1 in parallel trials in Europe and the United States to evaluate treatment with a self-inactivating (SIN) γ-retrovirus vector containing deletions in viral enhancer sequences expressing γc (SIN-γc).RESULTS All patients received bone marrow-derived CD34+ cells transduced with the SIN-γc vector, without preparative conditioning. After 12.1 to 38.7 months of follow-up, eight of the nine children were still alive. One patient died from an overwhelming adenoviral infection before reconstitution with genetically modified T cells. Of the remaining eight patients, seven had recovery of peripheral-blood T cells that were functional and led to resolution of infections. The patients remained healthy thereafter. The kinetics of CD3+ T-cell recovery was not significantly different from that observed in previous trials. Assessment of insertion sites in peripheral blood from patients in the current trial as compared with those in previous trials revealed significantly less clustering of insertion sites within LMO2, MECOM, and other lymphoid proto-oncogenes in our patients.CONCLUSIONS This modified γ-retrovirus vector was found to retain efficacy in the treatment of SCID-X1. The long-term effect of this therapy on leukemogenesis remains unknown. Copyright © 2014 Massachusetts Medical Society. All rights reserved.


Hacein-Bey Abina S.,Necker Childrens Hospital | Hacein-Bey Abina S.,Groupe Hospitalier University Ouest | Hacein-Bey Abina S.,CNRS Health Technology, Chemistry and Biology Unit | Hacein-Bey Abina S.,University Paris - Sud | And 59 more authors.
JAMA - Journal of the American Medical Association | Year: 2015

IMPORTANCE: Wiskott-Aldrich syndrome is a rare primary immunodeficiency associated with severe microthrombocytopenia. Partially HLA antigen-matched allogeneic hematopoietic stem cell (HSC) transplantation is often curative but is associated with significant comorbidity. OBJECTIVE: To assess the outcomes and safety of autologous HSC gene therapy in Wiskott-Aldrich syndrome. DESIGN, SETTING, AND PARTICIPANTS: Gene-corrected autologous HSCs were infused in 7 consecutive patients with severe Wiskott-Aldrich syndrome lacking HLA antigen-matched related or unrelated HSC donors (age range, 0.8-15.5 years; mean, 7 years) following myeloablative conditioning. Patients were enrolled in France and England and treated between December 2010 and January 2014. Follow-up of patients in this intermediate analysis ranged from 9 to 42 months. INTERVENTION: A single infusion of gene-modified CD34+ cells with an advanced lentiviral vector. MAIN OUTCOMES AND MEASURES: Primary outcomes were improvement at 24 months in eczema, frequency and severity of infections, bleeding tendency, and autoimmunity and reduction in disease-related days of hospitalization. Secondary outcomes were improvement in immunological and hematological characteristics and evidence of safety through vector integration analysis. RESULTS: Six of the 7 patients were alive at the time of last follow-up (mean and median follow-up, 28 months and 27 months, respectively) and showed sustained clinical benefit. One patient died 7 months after treatment of preexisting drug-resistant herpes virus infection. Eczema and susceptibility to infections resolved in all 6 patients. Autoimmunity improved in 5 of 5 patients. No severe bleeding episodes were recorded after treatment, and at last follow-up, all 6 surviving patients were free of blood product support and thrombopoietic agonists. Hospitalization days were reduced from a median of 25 days during the 2 years before treatment to a median of 0 days during the 2 years after treatment. All 6 surviving patients exhibited high-level, stable engraftment of functionally corrected lymphoid cells. The degree of myeloid cell engraftment and of platelet reconstitution correlated with the dose of gene-corrected cells administered. No evidence of vector-related toxicity was observed clinically or by molecular analysis. CONCLUSIONS AND RELEVANCE: This study demonstrated the feasibility of the use of gene therapy in patients with Wiskott-Aldrich syndrome. Controlled trials with larger numbers of patients are necessary to assess long-term outcomes and safety. Copyright 2015 American Medical Association. All rights reserved.


Van Der Loo J.C.M.,Cincinnati Childrens Hospital Medical Center | Swaney W.P.,Washington University in St. Louis | Grassman E.,Cincinnati Childrens Hospital Medical Center | Terwilliger A.,Cincinnati Childrens Hospital Medical Center | And 14 more authors.
Gene Therapy | Year: 2012

Patients with X-linked severe combined immunodeficiency (SCID-X1) were successfully cured following gene therapy with a gamma-retroviral vector (gRV) expressing the common gamma chain of the interleukin-2 receptor (IL2RG). However, 5 of 20 patients developed leukemia from activation of cellular proto-oncogenes by viral enhancers in the long-terminal repeats (LTR) of the integrated vector. These events prompted the design of a gRV vector with self-inactivating (SIN) LTRs to enhance vector safety. Herein we report on the production of a clinical-grade SIN IL2RG gRV pseudotyped with the Gibbon Ape Leukemia Virus envelope for a new gene therapy trial for SCID-X1, and highlight variables that were found to be critical for transfection-based large-scale SIN gRV production. Successful clinical production required careful selection of culture medium without pre-added glutamine, reduced exposure of packaging cells to cell-dissociation enzyme, and presence of cations in wash buffer. The clinical vector was high titer; transduced 68-70% normal human CD34 + cells, as determined by colony-forming unit assays and by xenotransplantation in immunodeficient NOD.CB17-Prkdc scid/J (nonobese diabetic/severe combined immunodeficiency (NOD/SCID)) and NOD.Cg-Prkdc scid Il2rg tm1Wjl/SzJ (NOD/SCID gamma (NSG))) mice; and resulted in the production of T cells in vitro from human SCID-X1 CD34 +cells. The vector was certified and released for the treatment of SCID-X1 in a multi-center international phase I/II trial. © 2012 Macmillan Publishers Limited All rights reserved.


Hacein-Bey-Abina S.,Necker Enfants Malades Hospital | Hacein-Bey-Abina S.,French Institute of Health and Medical Research | Hacein-Bey-Abina S.,Groupe Hospitalier University Ouest | Hacein-Bey-Abina S.,University of Paris Descartes | And 30 more authors.
New England Journal of Medicine | Year: 2010

BACKGROUND: The outcomes of gene therapy to correct congenital immunodeficiencies are unknown. We reviewed long-term outcomes after gene therapy in nine patients with X-linked severe combined immunodeficiency (SCID-X1), which is characterized by the absence of the cytokine receptor common γ chain. METHODS: The nine patients, who lacked an HLA-identical donor, underwent ex vivo retrovirus-mediated transfer of γ chain to autologous CD34+ bone marrow cells between 1999 and 2002. We assessed clinical events and immune function on long-term follow-up. RESULTS: Eight patients were alive after a median follow-up period of 9 years (range, 8 to 11). Gene therapy was initially successful at correcting immune dysfunction in eight of the nine patients. However, acute leukemia developed in four patients, and one died. Transduced T cells were detected for up to 10.7 years after gene therapy. Seven patients, including the three survivors of leukemia, had sustained immune reconstitution; three patients required immunoglobulin-replacement therapy. Sustained thymopoiesis was established by the persistent presence of naive T cells, even after chemotherapy in three patients. The T-cell-receptor repertoire was diverse in all patients. Transduced B cells were not detected. Correction of the immunodeficiency improved the patients' health. CONCLUSIONS: After nearly 10 years of follow-up, gene therapy was shown to have corrected the immunodeficiency associated with SCID-X1. Gene therapy may be an option for patients who do not have an HLA-identical donor for hematopoietic stem-cell transplantation and for whom the risks are deemed acceptable. This treatment is associated with a risk of acute leukemia. (Funded by INSERM and others.) Copyright © 2010 Massachusetts Medical Society.


Cartier N.,University of Paris Descartes | Hacein-Bey-Abina S.,Hopital Necker Enfants Malades | Hacein-Bey-Abina S.,University of Paris Descartes | Hacein-Bey-Abina S.,Groupe Hospitalier University Ouest | And 9 more authors.
Methods in Enzymology | Year: 2012

X-linked adrenoleukodystrophy (X-ALD) is a severe genetic demyelinating disease caused by a deficiency in ALD protein, an adenosine triphosphate-binding cassette transporter encoded by the ABCD1 gene. When performed at an early stage of the disease, allogeneic hematopoietic stem cell transplantation (HCT) can arrest the progression of cerebral demyelinating lesions. To overcome the limitations of allogeneic HCT, hematopoietic stem cell (HSC) gene therapy strategy aiming to perform autologous transplantation of lentivirally corrected cells was developed. We demonstrated the preclinical feasibility of HSC gene therapy for ALD based on the correction of CD34 + cells from X-ALD patients using an HIV1-derived lentiviral vector. These results prompted us to initiate an HSC gene therapy trial in two X-ALD patients who had developed progressive cerebral demyelination, were candidates for allogeneic HCT, but had no HLA-matched donors or cord blood. Autologous CD34 + cells were purified from the peripheral blood after G-CSF stimulation, genetically corrected ex vivo with a lentiviral vector encoding wild-type ABCD1 cDNA, and then reinfused into the patients after they had received full myeloablative conditioning. Over 3 years of follow-up, the hematopoiesis remained polyclonal in the two patients treated with 7-14 of granulocytes, monocytes, and T and B lymphocytes expressing the lentivirally encoded ALD protein. There was no evidence of clonal dominance or skewing based on the retrieval of lentiviral insertion repertoire in different hematopoietic lineages by deep sequencing. Cerebral demyelination was arrested 14 and 16 months, respectively, in the two treated patients, without further progression up to the last follow-up, a clinical outcome that is comparable to that observed after allogeneic HCT. Longer follow-up of these two treated patients and HSC gene therapy performed in additional ALD patients are however needed to evaluate the safety and efficacy of lentiviral HSC gene therapy in cerebral forms of X-ALD. © 2012 Elsevier Inc. All rights reserved.


Van Til N.P.,Erasmus Medical Center | Sarwari R.,Erasmus Medical Center | Visser T.P.,Erasmus Medical Center | Hauer J.,French Institute of Health and Medical Research | And 19 more authors.
Journal of Allergy and Clinical Immunology | Year: 2014

Background Recombination-activating gene 1 (RAG1) deficiency results in severe combined immunodeficiency (SCID) caused by a complete lack of T and B lymphocytes. If untreated, patients succumb to recurrent infections. Objectives We sought to develop lentiviral gene therapy for RAG1-induced SCID and to test its safety. Methods Constructs containing the viral spleen-focus-forming virus (SF), ubiquitous promoters, or cell type-restricted promoters driving sequence-optimized RAG1 were compared for efficacy and safety in sublethally preconditioned Rag1-/- mice undergoing transplantation with transduced bone marrow progenitors. Results Peripheral blood CD3+ T-cell reconstitution was achieved with SF, ubiquitous promoters, and cell type-restricted promoters but 3- to 18-fold lower than that seen in wild-type mice, and with a compromised CD4+/CD8+ ratio. Mitogen-mediated T-cell responses and T cell-dependent and T cell-independent B-cell responses were not restored, and T-cell receptor patterns were skewed. Reconstitution of mature peripheral blood B cells was approximately 20-fold less for the SF vector than in wild-type mice and often not detectable with the other promoters, and plasma immunoglobulin levels were abnormal. Two months after transplantation, gene therapy-treated mice had rashes with cellular tissue infiltrates, activated peripheral blood CD44+CD69+ T cells, high plasma IgE levels, antibodies against double-stranded DNA, and increased B cell-activating factor levels. Only rather high SF vector copy numbers could boost T- and B-cell reconstitution, but mRNA expression levels during T- and B-cell progenitor stages consistently remained less than wild-type levels. Conclusions These results underline that further development is required for improved expression to successfully treat patients with RAG1-induced SCID while maintaining low vector copy numbers and minimizing potential risks, including autoimmune reactions resembling Omenn syndrome. © 2013 American Academy of Allergy, Asthma & Immunology.


Cavazzana M.,Necker Childrens Hospital | Cavazzana M.,Groupe Hospitalier University Ouest | Cavazzana M.,University of Paris Pantheon Sorbonne | Cavazzana M.,French Institute of Health and Medical Research | And 9 more authors.
Current Opinion in Allergy and Clinical Immunology | Year: 2014

Progress in the treatment of primary immune deficiency with HSCT requires a better understanding of the pathophysiology and specificity of each of these diseases, allowing us to determine the best options in terms of donor, conditioning regimen, modification of the allograft and immunosuppressive therapy. Alternative therapies - such as gene therapy - emerge as an interesting option for some PIDs. Copyright © Lippincott Williams & Wilkins.


Fischer A.,French Institute of Health and Medical Research | Fischer A.,University of Paris Descartes | Fischer A.,Necker Childrens Hospital | Hacein-Bey-Abina S.,French Institute of Health and Medical Research | And 7 more authors.
Journal of Allergy and Clinical Immunology | Year: 2011

Gene therapy has become an option for the treatment of 2 forms of severe combined immunodeficiency (SCID): X-linked SCID and adenosine deaminase deficiency. The results of clinical trials initiated more than 10 years ago testify to sustained and reproducible correction of the underlying T-cell immunodeficiency. Successful treatment is based on the selective advantage conferred on T-cell precursors through their expression of the therapeutic transgene. However, "first-generation" retroviral vectors also caused leukemia in some patients with X-linked SCID because of the constructs' tendency to insert into active genes (eg, proto-oncogenes) in progenitor cells and transactivate an oncogene through a viral element in the long terminal repeat. These elements have been deleted from the vectors now in use. Together with the use of lentiviral vectors (which are more potent for transducing stem cells), these advances should provide a basis for the safe and effective extension of gene therapy's indications in the field of primary immunodeficiencies. Nevertheless, this extension will have to be proved by examining the results of the ongoing clinical trials. © 2011 American Academy of Allergy, Asthma & Immunology.

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