[What is the cross-disciplinary pathway for a patient receiving gene therapy?] / Quel parcours transversal pour un patient recevant une thérapie génique ?

The Department of Hematology-Immunology, headed by Professor Jean-Hugues Dalle, is the leading department in France for the care of patients receiving pediatric hematopoietic stem cell transplants. Since 2018, it has been a "major player" in the development of innovative treatments, such as gene therapy. To date, it is the only care service in France, which offers this treatment to stop the neurodegenerative progression of two genetic diseases, in collaboration with the neuropediatric service of the Kremlin-Bicêtre hospital headed by Prof Kumaran Deiva, in conjunction with the national reference center for rare disaeses didicated to leucodystrophies. It is a complex care that requires all the actors a cooperation (parents-children-caregivers).

[Can academic structures improve access to CAR-T cells?] / Les structures académiques peuvent-elles permettre une amélioration de l'accessibilité aux CAR-T cells ?

In France, hospital cell therapy units have not been authorised to routinely produce chimeric antigen receptor T lymphocytes (CAR-T cells), which would then be referred to as academic CAR-T cells. CAR-T cells are classified as advanced therapy medicinal products and correspond to genetically modified T lymphocytes ex vivo. The CAR-T cell production process is complex and requires scientific and technical expertise to meet the acceptance criteria of the pharmaceutical quality system. The most commonly used method for genetically modifying T lymphocytes is viral transduction (lentiviral or retroviral), which requires prior access to a batch of good manufacturing practice (GMP) grade viral vector. Because of its cost, this reagent is the main limiting factor for developing CAR-T cells. A CAR-T cell produced by an industrial company is expensive (around €350,000 per injection) and the time taken by the manufacturer to make it available to the clinician can vary from three to five weeks. By meeting the economic and ecological challenges, can academic structures improve access to CAR-T cells? In this article, we present the elements necessary for the feasibility of setting up CAR-T cell production in an academic structure.

[CRISPR/Cas9: From research to therapeutic application]. / CRISPR/Cas9 : de la recherche à l'application thérapeutique.

For several decades, genome engineering has raised interest among many researchers and physicians in the study of genetic disorders and their treatments. Compared to its predecessors, zinc-finger nucleases (ZFN) and transcription activator-like effectors (TALEN), clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) is currently the most efficient molecular tool for genome editing. This system, originally identified as a bacterial adaptive immune system, is capable of cutting and modifying any gene of a large number of living organisms. Numerous trials using this technology are being developed to provide effective treatment for several diseases, such as cancer, cardiovascular and ophthalmic disorders. In research, this technology is increasingly used for genetic disease modelling, providing meaningful models of relevant studies as well as a better understanding of underlying pathological mechanisms. Many molecular tools are now available to put this technique into practice in laboratories, and despite the technical and ethical issues raised by manipulation of the genome, CRIPSR/Cas9 offers a new breath of hope for therapeutic research around the world.

[Medical treatments in Leber's hereditary optic neuropathy]. / Traitements médicaux dans la neuropathie optique héréditaire de Leber.

Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease caused by a mutation of mitochondrial DNA. LHON targets retinal ganglion cells (RGC), whose axons form the optic nerve. The mutation that leads to LHON is silent until an unknown trigger causes dysfunction of complex I in the mitochondria of RGC. This results in discontinuation of RGC energy production and, eventually, RGC apoptosis. Patients experience bilateral sequential central scotoma over the course of a few months, with a minority recovering some vision more than 1 year after the onset of visual loss. No pharmacological treatment is recommended unless patients are symptomatic in at least one eye, as most LHON mutation carriers never experience visual loss. Research has been focused on treatments that are thought to restore the mitochondrial electron transport chain in RGC in patients with recent disease onset (<1 year). Significant advances have been made in evaluating free radical cell scavengers and gene therapy as potential treatments for LHON. Although promising, the results of clinical trials have been mixed. In patients with chronic visual loss for more than 1 year, treatment that restores vision is yet to be discovered. In this review, we summarize management strategies for patients with LHON before, during, and after the loss of vision, explain the rationale and effectiveness of previous and current treatments, and report findings about emerging treatments.

[CAR-T cells gene therapy medicines: Regulatory status and pharmaceutical circuits in Europe and France]. / Les médicaments de thérapie génique CAR-T cells : statuts réglementaires et circuits pharmaceutiques en Europe et en France.

CAR-T cells belong to a new class of biological medicines, referred to as Advanced Therapy Medicinal Products (ATMPs). Despite the cellular component, according to the regulatory definition, CAR-T cells are gene therapy medicines, a sub-category of ATMPs, since their therapeutic effect is the result of their genetic modification. The specificity and the complexity of these innovative drugs have required a complete reorganization of the hospital and pharmaceutical circuits, from the cell collection to the drug administration to the patient. Indeed, increased interaction and collaboration between different healthcare professionals is essential in order to guarantee the quality and safety of these innovative medicines.

[Implementation of a new gene therapy in ophthalmology: Regulatory and organizational issues]. / Mise en place d'une nouvelle thérapie génique en ophtalmologie : aspects réglementaires et organisationnels.

Voretigene neparvovec (VN) is the first gene therapy in ophthalmology for patients with RPE65-mediated hereditary retinal dystrophy. It has recently obtained European market approval, which is subject to strict regulatory and organizational conditions for its use. Here, we analyze the main studies supporting the authorization of this new therapy and describe the necessary steps to take at a hospital level for optimal administration to patients following current regulations.

Gene therapy and cell therapy for the management of radiation damages to healthy tissues: Rationale and early results.

Nowadays, ionizing radiations have numerous applications, especially in medicine for diagnosis and therapy. Pharmacological radioprotection aims at increasing detoxification of free radicals. Radiomitigation aims at improving survival and proliferation of damaged cells. Both strategies are essential research area, as non-contained radiation can lead to harmful effects. Some advances allowing the comprehension of normal tissue injury mechanisms, and the discovery of related predictive biomarkers, have led to developing several highly promising radioprotector or radiomitigator drugs. Next to these drugs, a growing interest does exist for biotherapy in this field, including gene therapy and cell therapy through mesenchymal stem cells. In this review article, we provide an overview of the management of radiation damages to healthy tissues via gene or cell therapy in the context of radiotherapy. The early management aims at preventing the occurrence of these damages before exposure or just after exposure. The late management offers promises in the reversion of constituted late damages following irradiation.

Transfusing children with hemoglobinopathies.

Thalassemia and sickle cell disease (SCD) are among the most common inherited diseases worldwide. Red blood cell transfusion is a cornerstone of their treatment, but its indications have significantly changed over the past years. New therapies are emerging in both syndromes: among them, hematopoietic stem cell transplantation is now routinely proposed, and gene therapy has shown promising preliminary results.

[CAR-T cells: Lymphocytes that express a chimeric antigen receptor]. / CAR-T cells : lymphocytes exprimant un récepteur chimérique à l'antigène.

CAR-T cells are genetically modified human lymphocytes and gene therapy medicinal products. They are developed to treat cancers that express a membrane antigen targeted by the CAR. The FDA approved the two first-in-class medicinal products in 2017 and EMA in August 2018; both are autologous CAR-T cells targeting CD19 that is expressed at the surface of normal B-cells throughout their differentiation, and on B-cell lymphoid malignancies. Clinical efficacy was demonstrated for B-cell acute lymphoblastic leukemias, non-Hodgkin's lymphoma and chronic lymphocytic leukemia, although the marketing authorizations are less liberal in terms of indications. Manufacturing of these personalized treatments necessitates that a novel organization and supply chain be set in place, to ensure product preservation, patient safety and compliance with complex regulatory requirements. Side effects are commensurate with clinical efficacy and can be life-threatening: proper management imposes tight coordination between various specialists, particularly between hematologists and intensive care practitioners. High pricing for these treatments is part of a long-term trend for increasing costs of innovations in hematology and oncology; it questions the ability of healthcare systems to sustain their reimbursement.

[What's new in research?] / Quoi de neuf en recherche?

A traditional lecture given during the annual meeting of the French Society of Dermatology in Paris summarizes the highlights of the scientific literature over the past year. In the current article the selection of the 2017-2018 period retains the following areas of interest: role of microbiome in the response to anti-PD-1 and in autoimmunity, PI3Kδ inhibitors in autoimmune bullous diseases, diagnostic and therapeutic applications of CRISPR/Cas, arrival of CAR-T cells therapy into clinical practice, gene therapy successes, use of targeted therapies in genodermatoses and integration of genetics in primary care. © 2018 Elsevier Masson SAS. All rights reserved.

Inhibition of DNA methyltransferase-1 instigates the expression of DNA methyltransferase-3a in angioplasty-induced restenosis.

Increased expression of DNA methyltransferase-1 (DNMT1) associates with the progression of many human diseases. Because DNMT1 induces cell proliferation, drugs that inhibit DNMT1 have been used to treat proliferative diseases. Because these drugs are nonspecific inhibitors of DNMT1, subsidiary events or the compensatory mechanisms that are activated in the absence of DNMT1 limit their therapeutic application. Here, we studied the molecular mechanisms that occur during angioplasty-induced restenosis and found that DNMT1 inhibition in both in vitro and in vivo approaches resulted in the induction of DNA methyltransferase-3a (DNMT3a) expression. In vascular smooth muscle cells (VSMCs), the microRNA hsa-miR-1264 mimic, specifically inhibiting DNMT1, induced nuclear expression of DNMT3a. On the contrary, there was no induced expression of DNMT3a in VSMCs that were transfected with hsa-miR-1264 inhibitor. Further, ectopic expression of suppressor of cytokine signaling 3 (SOCS3) through adeno-associated virus (AAV)-mediated gene delivery in the coronary arteries of Yucatan microswine showed inhibition of both DNMT1 and DNMT3a in vivo. These findings show the existence of an inter-regulatory mechanism between DNMT1 and DNMT3a where, in the absence of DNMT1, induction of DNMT3a compensates for the loss of DNMT1 functions, suggesting that the inhibition of both DNMT1 and DNMT3a are required to prevent restenosis.

L'émergence des traitements par cellules CAR-T dans les lymphomes.

EMERGING THERAPIES USING CAR-T CELLS IN LYMPHOMA: After the promising results obtained in North American academic centers suggesting the curative potential of these treatments, the development of T cells carrying a chimeric antigen receptor (CAR-T) directed against the CD19 antigen has experienced rapid developments in recent years. Three major trials (each involving about 100 patients with relapsed or refractory aggressive B-cell lymphoma) were conducted and evaluated the efficacy of these treatments (Zuma-1, Juliet and Transcend). Tumor responses are observed in 52% to 82% of patients, with a best complete response (CR) rate of 40% to 58%. Although some patients with early CR may relapse rapidly, the quality of the response appears to improve over time for other patients in partial response, all of which result in a proportion of patients with prolonged CR by approximately 30% to 40% (up to more than one year after treatment). Toxicities (mostly early and reversible) are mainly represented by the cytokine release syndrome (severe in 1% to 22% of patients) and neurological disorders sometimes severe (in 12% to 31% of patients), while other patients develop cytopenias or hypogammaglobulinemia. The updating of these studies over time and the new developments (in the improvement of their conception and in their use) of the CAR-T will allow to better defining the place of these innovative and promising treatments in the therapeutic strategy of patients with lymphoma. Cet article fait partie du numéro supplément Les cellules CAR-T : une révolution thérapeutique ? réalisé avec le soutien institutionnel des partenaires Gilead : Kite et Celgene.

Rôle du pharmacien hospitalier dans le circuit d'une catégorie de Médicament de Thérapie Innovante : les lymphocytes T exprimant un Récepteur Chimérique à l'Antigène.

ROLE OF THE HOSPITAL PHARMACIST IN THE MANAGEMENT OF A CATEGORY OF ADVANCED THERAPY MEDICINAL PRODUCT: CHIMERIC ANTIGEN RECEPTOR T-CELLS: Chimeric Antigen Receptor T-cells (CART) belongs to a new class of medicine, Advanced Therapy Medicinal Product, such as define by the European Regulation 1394/2007, and more exactly to the category of gene therapy medicinal product. Their status of medicine, as well as genetically modified organisms, imposes a particular circuit at hospital while maintaining a way over the Hospital Pharmacy. The manipulation of genetically modified cells is not usual in pharmacy. It requires, besides the acquisition of new skills, a not insignificant reorganization of the teams and the rooms of the pharmacy as well as an adapted training of the staff. A good communication is essential between the various actors of the circuit. The hospital pharmacist plays a key role in the implementation of a circuit adapted to this new type of medicine. This article aims to identify the roles of the hospital pharmacist and more generally of the pharmacy in the management of CART. We shall detail the specificities of this type of medicine in every stage of the circuit and the adaptations necessary to realize to guarantee the quality and the safety of the treatment by CART. Beyond the implementation of the circuit in the hospital, the pharmacist has an important role to be played in the follow-up of the patients after administration in view of the complexity of the side effects and a certain role in the training of the teams to this new medicine. Cet article fait partie du numéro supplément Les cellules CAR-T : une révolution thérapeutique ? réalisé avec le soutien institutionnel des partenaires Gilead : Kite et Celgene.

Precision genome editing in the CRISPR era.

With the introduction of precision genome editing using CRISPR-Cas9 technology, we have entered a new era of genetic engineering and gene therapy. With RNA-guided endonucleases, such as Cas9, it is possible to engineer DNA double strand breaks (DSB) at specific genomic loci. DSB repair by the error-prone non-homologous end-joining (NHEJ) pathway can disrupt a target gene by generating insertions and deletions. Alternatively, Cas9-mediated DSBs can be repaired by homology-directed repair (HDR) using an homologous DNA repair template, thus allowing precise gene editing by incorporating genetic changes into the repair template. HDR can introduce gene sequences for protein epitope tags, delete genes, make point mutations, or alter enhancer and promoter activities. In anticipation of adapting this technology for gene therapy in human somatic cells, much focus has been placed on increasing the fidelity of CRISPR-Cas9 and increasing HDR efficiency to improve precision genome editing. In this review, we will discuss applications of CRISPR technology for gene inactivation and genome editing with a focus on approaches to enhancing CRISPR-Cas9-mediated HDR for the generation of cell and animal models, and conclude with a discussion of recent advances and challenges towards the application of this technology for gene therapy in humans.

Gene therapy: Myth or reality?

Gene therapy has become a reality, although still a fragile one. Clinical benefit has been achieved over the last 17years in a limited number of medical conditions for which pathophysiological studies determined that they were favorable settings. They include inherited disorders of the immune system, leukodystrophies, possibly hemoglobinopathies, hemophilia B, and retinal dystrophies. Advances in the treatment of B-cell leukemias and lymphomas have also been achieved. Advances in vector development and possible usage of gene editing may lead to significant advances over the next years.

[New therapies for cystic fibrosis targeting the CFTR gene or the CFTR protein]. / Nouvelles thérapeutiques de la mucoviscidose ciblant le gène ou la protéine CFTR.

BACKGROUND: The treatment of cystic fibrosis has been symptom-based for a number of years. New therapies that aim to improve CFTR protein function are now emerging. CURRENT SCIENTIFIC KNOWLEDGE: The results of gene therapy has been modest but a recent clinical trial shows a positive effect on FEV1. Recent research has focused primarily on CFTR protein function. Significant respiratory improvement (an average 10% FEV1 increase and a decrease in the frequency of exacerbations) has been achieved with ivacaftor, a CFTR potentiator, in patients with gating mutations, resulting in its marketing authorization (in 2012 for the G551D mutation and in 2015 for rarer mutations). In phe508del homozygous patients, the combination of ivacaftor with a CFTR corrector (lumacaftor) has also led to respiratory improvement, albeit less impressive. The effectiveness of ataluren in patients with nonsense mutations is being evaluated. OUTLOOK: New CFTR correctors and potentiators are being developed. CFTR protein therapy could change the course of the disease but cost/effectiveness issues should not be overlooked. CONCLUSION: Ivacaftor can be prescribed in CF patients with a class 3 mutation from the age of 6 years. The Orkambi® will soon be available for homozygous phe508del patients from the age of 12 years.

Biotherapies for Parkinson disease.

The clinical use of biotherapies in Parkinson disease already has 30 years' history. The transplantation of dopamine fetal cells in the striatum of advanced patients has proved to be relevant in some patients but randomized efficacy trials in the US have provided disappointing results. However, cell therapies might come back on stage with the use of stem cells in the future. Gene therapy is a more recent strategy relying on viral vectors able to transduce genes coding either for the enzymes that can increase neurotransmitters production or genes for trophic factors. Several approaches have been developed in PD and have been experimented in patients. Although, some of the studies have evidenced insufficient clinical benefit, other programs, such as those using dopamine replacement techniques are promising. We find fresh hope in this field that might be the future of PD treatment. It remains however that advanced PD might not be the ideal condition to properly benefit from biotherapies and there is a need of studies at earlier stages of the disease, a time where major change in the disease course might be expected.