[Genetically modified regulatory T cells: therapeutic concepts and regulatory aspects].

Adoptive T‑cell therapies are emerging tools to combat various human diseases. CAR‑T cells are approved and marketed as last line therapeutics in advanced B‑cell lymphomas and leukemias. TCR-engineered T cells are being evaluated in clinical trials for a variety of hematological and solid tumors.

Cytokine-induced interleukin-1 receptor antagonist protein expression in genetically engineered equine mesenchymal stem cells for osteoarthritis treatment.

Background: A combination of tissue engineering methods employing mesenchymal stem cells (MSCs) together with gene transfer takes advantage of innovative strategies and highlights a new approach for targeting osteoarthritis (OA) and other cartilage defects. Furthermore, the development of systems allowing tunable transgene expression as regulated by natural disease-induced substances is highly desirable.

Methods: Bone marrow-derived equine MSCs were transduced with a lentiviral vector expressing interleukin-1 receptor antagonist (IL-1Ra) gene under the control of an inducible nuclear factor-kappa B-responsive promoter and IL-1Ra production upon pro-inflammatory cytokine stimulation [tumor necrosis factor (TNF)α, interleukin (IL)-1β] was analysed.

Clinical translation and regulatory aspects of CAR/TCR-based adoptive cell therapies-the German Cancer Consortium approach.

Adoptive transfer of T cells genetically modified by TCRs or CARs represents a highly attractive novel therapeutic strategy to treat malignant diseases. Various approaches for the development of such gene therapy medicinal products (GTMPs) have been initiated by scientists in recent years. To date, however, the number of clinical trials commenced in Germany and Europe is still low.

Human Genome Editing in the Clinic: New Challenges in Regulatory Benefit-Risk Assessment.

As genome editing rapidly progresses toward the realization of its clinical promise, assessing the suitability of current tools and processes used for its benefit-risk assessment is critical. Although current regulations may initially provide an adequate regulatory framework, improvements are recommended to overcome several existing technology-based safety and efficacy issues.

Going non-viral: the Sleeping Beauty transposon system breaks on through to the clinical side.

Molecular medicine has entered a high-tech age that provides curative treatments of complex genetic diseases through genetically engineered cellular medicinal products. Their clinical implementation requires the ability to stably integrate genetic information through gene transfer vectors in a safe, effective and economically viable manner. The latest generation of Sleeping Beauty (SB) transposon vectors fulfills these requirements, and may overcome limitations associated with viral gene transfer vectors and transient non-viral gene delivery approaches that are prevalent in ongoing pre-clinical and translational research.

Tropism, intracerebral distribution, and transduction efficiency of HIV- and SIV-based lentiviral vectors after injection into the mouse brain: a qualitative and quantitative in vivo study.

Lentiviruses are suitable to transfer potential therapeutic genes into non-replicating cells such as neurons, but systematic in vivo studies on transduction of neural cells within the complete brain are missing. We analysed the distribution of transduced cells with respect to brain structure, virus tropism, numbers of transduced neurons per brain, and influence of the Vpx or Vpr accessory proteins after injection of vectors based on SIVsmmPBj, HIV-2, and HIV-1 lentiviruses into the right striatum of the mouse brain. Transduced cells were found ipsilaterally around the injection canal, in corpus striatum and along corpus callosum, irrespective of the vector type.

Report of the International Regulatory Forum on Human Cell Therapy and Gene Therapy Products.

The development of human cell therapy and gene therapy products has progressed internationally. Efforts have been made to address regulatory challenges in the evaluation of quality, efficacy, and safety of the products. In this forum, updates on the specific challenges in quality, efficacy, and safety of products in the view of international development were shared through the exchange of information and opinions among experts from regulatory authorities, academic institutions, and industry practitioners.

Inflammation-induced transgene expression in genetically engineered equine mesenchymal stem cells.

Background: Osteoarthritis, a chronic and progressive degenerative joint disorder, ranks amongst the top five causes of disability. Given the high incidence, associated socioeconomic costs and the absence of effective disease-modifying therapies of osteoarthritis, cell-based treatments offer a promising new approach. Owing to their paracrine, differentiation and self-renewal abilities, mesenchymal stem cells (MSCs) have great potential for regenerative medicine, which might be further enhanced by targeted gene therapy.

Marketing Regulatory Oversight of Advanced Therapy Medicinal Products (ATMPs) in Europe: The EMA/CAT Perspective.

With the release of Regulation 1394/2007, a new framework for gene and cell therapy medicinal products and tissue-engineered products was established in the European Union. For all three product classes, called advanced therapy medicinal products, a centralised marketing authorisation became mandatory. The European Medicines Agency (EMA) together with its Committee for Advanced Therapies, Committee for Human Medicinal Products and the network of national agencies is responsible for scientific evaluation of the marketing authorisation applications.

Regulation of Clinical Trials with Advanced Therapy Medicinal Products in Germany.

In the European Union, clinical trials for Advanced Therapy Medicinal Products are regulated at the national level, in contrast to the situation for a Marketing Authorisation Application, in which a centralised procedure is foreseen for these medicinal products. Although based on a common understanding regarding the regulatory requirement to be fulfilled before conduct of a clinical trial with an Advanced Therapy Investigational Medicinal Product, the procedures and partly the scientific requirements for approval of a clinical trial application differ between the European Union Member States. This chapter will thus give an overview about the path to be followed for a clinical trial application and the subsequent approval process for an Advanced Therapy Investigational Medicinal Product in Germany and will describe the role of the stakeholders that are involved.

[Therapeutic approaches using genetically modified cells].

Medicinal products containing genetically modified cells are, in most cases, classified as gene therapy and cell therapy medicinal products. Although no medicinal product containing genetically modified cells has been licensed in Europe yet, a variety of therapeutic strategies using genetically modified cells are in different stages of clinical development for the treatment of acquired and inherited diseases. In this chapter, several examples of promising approaches are presented, with an emphasis on gene therapy for inherited immunodeficiencies and on tumour immunotherapy with genetically modified T-cells expressing a chimeric antigen receptor or a recombinant T-cell receptor.

Cell therapy clinical trials in Germany--Critical aspects of quality data content: Summary of meeting presentation.

This article is summarizing a presentation given by the author at the International Alliance for Biological Standardization and Japan Science and Technology Agency (IABS-JST) Joint Workshop on "Challenges towards sound scientific regulation of cell therapy products" held at the Kyoto International Conference Center, Kyoto Japan on March 7-8, 2014. The main topics of the presentation were to give a short overview about the regulatory approval process for clinical trials in Germany and to summarize important manufacturing aspects of cell based medicinal products (CBMPs) which are intended to be studied in clinical trials in Germany.

A roadmap toward clinical translation of genetically-modified stem cells for treatment of HIV.

During the past decade, successful gene therapies for immunodeficiencies were finally brought to the clinic. This was accomplished through new gene therapy vectors and improved procedures for genetic modification of autologous hematopoietic stem cells. For HIV, autologous hematopoietic stem cell (HSC) gene therapy with 'anti-HIV genes' promises a functional cure for the disease.

Standardization of Good Manufacturing Practice-compliant production of bone marrow-derived human mesenchymal stromal cells for immunotherapeutic applications.

Background Aims: Human mesenchymal stem or stromal cells (MSCs) represent a potential resource not only for regenerative medicine but also for immunomodulatory cell therapies. The application of different MSC culture protocols has significantly hampered the comparability of experimental and clinical data from different laboratories and has posed a major obstacle for multicenter clinical trials. Manufacturing of cell products for clinical application in the European Community must be conducted in compliance with Good Manufacturing Practice and requires a manufacturing license.

Safety assessment of biolistic DNA vaccination.

DNA-based vector systems have been widely studied as new modalities for the prevention and treatment of human diseases. As for all other medicinal products, safety is an important aspect in the evaluation of such products. In this chapter we reflect on the basic safety issues which have been raised with respect to preventive and therapeutic DNA vaccines, including insertional mutagenesis in case of chromosomal integration, possible formation of anti-DNA antibodies, induction of autoimmune responses and/or immunological tolerance.

Evaluation of a gene-directed enzyme-product therapy (GDEPT) in human pancreatic tumor cells and their use as in vivo models for pancreatic cancer.

Background: Gene-directed enzyme prodrug therapy (GDEPT) is a two-step treatment protocol for solid tumors that involves the transfer of a gene encoding a prodrug-activating enzyme followed by administration of the inactive prodrug that is subsequently activated by the enzyme to its tumor toxic form. However, the establishment of such novel treatment regimes to combat pancreatic cancer requires defined and robust animal model systems.

Methods: Here, we comprehensively compared six human pancreatic cancer cell lines (PaCa-44, PANC-1, MIA PaCa-2, Hs-766T, Capan-2, and BxPc-3) in subcutaneous and orthotopical mouse models as well as in their susceptibility to different GDEPTs.

Influence of vector design and host cell on the mechanism of recombination and emergence of mutant subpopulations of replicating retroviral vectors.

Background: The recent advent of murine leukaemia virus (MLV)-based replication-competent retroviral (RCR) vector technology has provided exciting new tools for gene delivery, albeit the advances in vector efficiency which have been realized are also accompanied by a set of fresh challenges. The expression of additional transgene sequences, for example, increases the length of the viral genome, which can lead to reductions in replication efficiency and in turn to vector genome instability. This necessitates efforts to analyse the rate and mechanism of recombinant emergence during the replication of such vectors to provide data which should contribute to improvements in RCR vector design.

Transgene expression facilitated by the v-src splice acceptor can impair replication kinetics and lead to genomic instability of Rous sarcoma virus-based vectors.

Rous sarcoma virus (RSV) can be used for the simple generation of high-titer replication-competent retroviral (RCR) vectors. Retroviruses undergo frequent genomic recombination, however, and vectors with reduced replication kinetics are rapidly overgrown by mutant forms. Vector design is hence critical to vector efficacy.

Effects of viral strain, transgene position, and target cell type on replication kinetics, genomic stability, and transgene expression of replication-competent murine leukemia virus-based vectors.

The limited efficiency of in vivo gene transfer by replication-deficient retroviral vectors remains an obstacle to achieving effective gene therapy for solid tumors. One approach to circumvent this problem is the use of replication-competent retroviral vectors. However, the application of such vectors is at a comparatively early stage and the effects which virus strain, transgene cassette position, and target cell can exert on vector spread kinetics, genomic stability, and transgene expression levels remain to be fully elucidated.