Computational fluid dynamics modeling,a novel,and effective approach for developing scalable cell therapy manufacturing processes

Induced pluripotent stem cells (iPSCs) hold great potential to generate novel, curative cell therapy products. However, current methods to generate these novel therapies lack scalability, are labor-intensive, require a large footprint, and are not suited to meet clinical and commercial demands. Therefore, it is necessary to develop scalable manufacturing processes to accommodate the generation of high-quality iPSC derivatives under controlled conditions. The current scale-up methods used in cell therapy processes are based on empirical, geometry-dependent methods that do not accurately represent the hydrodynamics of 3D bioreactors. These methods require multiple iterations of scale-up studies, resulting in increased development cost and time. Here we show a novel approach using computational fluid dynamics modeling to effectively scale-up cell therapy manufacturing processes in 3D bioreactors. Using a GMP-compatible iPSC line, we translated and scaled-up a small-scale cardiomyocyte differentiation process to a 3-L computer-controlled bioreactor in an efficient manner, showing comparability in both systems.     

The systematic production of cells for cell therapies

Stem cells have emerged as the starting material of choice for bioprocesses to produce cells and tissues to treat degenerative, genetic, and immunological disease. Translating the biological properties and potential of stem cells into therapies will require overcoming significant cell-manufacturing and regulatory challenges. Bioprocess engineering fundamentals, including bioreactor design and process control, need to be combined with cellular systems biology principles to guide the development of next-generation technologies capable of producing cell-based products in a safe, robust, and cost-effective manner. The step-wise implementation of these bioengineering strategies will enhance cell therapy product quality and safety, expediting clinical development.     

Cellular and soluble markers of tumor angiogenesis: From patient selection to the identification of the most appropriate postresistance therapy

Antiangiogenic drugs are now intensively used in clinical oncology, but some drawbacks still hamper their development. First, it is frequently unclear what patient subpopulation is likely to gain clinical benefit from these expensive therapies; second, there is evidence of (sometimes rapid) development of drug resistance in many patients; third, the results of some preclinical and clinical studies have suggested acceleration of malignant cell aggressiveness when some antiangiogenic therapies are terminated. Here we discuss the role of soluble molecules and cellular markers of neoplastic angiogenesis for patient selection and follow-up during treatment. These markers should help clinicians to decide the right therapy, advise them of the generation of mechanisms of drug resistance during antiangiogenic treatment, and finally suggest the most appropriate next line of therapy according to the new patterns of cancer vascularization induced by antiangiogenic therapies.     

Advanced therapies for the treatment of hemophilia: future perspectives

Monogenic diseases are ideal candidates for treatment by the emerging advanced therapies, which are capable of correcting alterations in protein expression that result from genetic mutation. In hemophilia A and B such alterations affect the activity of coagulation factors VIII and IX, respectively, and are responsible for the development of the disease. Advanced therapies may involve the replacement of a deficient gene by a healthy gene so that it generates a certain functional, structural or transport protein (gene therapy); the incorporation of a full array of healthy genes and proteins through perfusion or transplantation of healthy cells (cell therapy); or tissue transplantation and formation of healthy organs (tissue engineering). For their part, induced pluripotent stem cells have recently been shown to also play a significant role in the fields of cell therapy and tissue engineering. Hemophilia is optimally suited for advanced therapies owing to the fact that, as a monogenic condition, it does not require very high expression levels of a coagulation factor to reach moderate disease status. As a result, significant progress has been possible with respect to these kinds of strategies, especially in the fields of gene therapy (by using viral and non-viral vectors) and cell therapy (by means of several types of target cells). Thus, although still considered a rare disorder, hemophilia is now recognized as a condition amenable to gene therapy, which can be administered in the form of lentiviral and adeno-associated vectors applied to adult stem cells, autologous fibroblasts, platelets and hematopoietic stem cells; by means of non-viral vectors; or through the repair of mutations by chimeric oligonucleotides. In hemophilia, cell therapy approaches have been based mainly on transplantation of healthy cells (adult stem cells or induced pluripotent cell-derived progenitor cells) in order to restore alterations in coagulation factor expression.     

CAR-T cell therapy in India requires a paradigm shift in training,education and health care processes

Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the treatment of some kinds of cancers. Hundreds of companies and academic institutions are collaborating to develop gene-modified cell therapies using novel targets, different cell types, and manufacturing processes of autologous and allogenic cell therapies. The individualized, custom-made autologous CAR-T cell production platform remains a significant limiting factor for its large-scale clinical application. In this respect, the advances in standardization and automation of the process can have considerable impact on cost reduction. Development of off-the-shelf, ready-to-use universal killer cells can enable scaling up. Despite the wide use of this cell therapy in the United States, Europe and China, its development is limited in developing countries in Southeast Asia, Africa and Latin America. In this review, we focus on good manufacturing practices–compliant manufacturing requirements, operational logistics, and regulatory processes that need to be considered for high-quality gene-modified cell therapies from an Indian perspective. We also list the potential strategies to overcome challenges associated with translation to affordability and scalability.     

Progressing a human embryonic stem-cell-based regenerative medicine therapy towards the clinic

Since the first publication of the derivation of human embryonic stem cells in 1998, there has been hope and expectation that this technology will lead to a wave of regenerative medicine therapies with the potential to revolutionize our approach to managing certain diseases. Despite significant resources in this direction, the path to the clinic for an embryonic stem-cell-based regenerative medicine therapy has not proven straightforward, though in the past few years progress has been made. Here, with a focus upon retinal disease, we discuss the current status of the development of such therapies. We also highlight some of our own experiences of progressing a retinal pigment epithelium cell replacement therapy towards the clinic.     

干细胞移植治疗心力衰竭的研究进展

由于心肌梗死发作等原因可造成心肌受损、心力衰竭。干细胞可以向心肌细胞定向分化,这使得通过细胞移植治疗心力衰竭成为可能。简要综述了有望用于移植的干细胞,以及目前实验与临床研究进展和面临的问题。     

A population analysis of VEGF transgene expression and secretion

The induction of therapeutic angiogenesis with gene therapy approaches has received considerable interest and some limited clinical success. A major drawback to this approach is a lack of understanding of the pharmacokinetics of therapeutic protein delivery. This has become increasingly more relevant as recent studies have illustrated a defined therapeutic window for angiogenic protein secretion into the local microenvironment. For cell based gene therapies, with cells widely distributed throughout the tissue, this implies that any individual cell must attain a specific secretion rate to produce a local angiogenic response. Here we report a reproducible technique enabling the study of growth factor secretion from individual cells following transient plasmid transfection. We demonstrate significant variability in single cell vascular endothelial growth factor (VEGF) secretion with the majority of total protein secretion arising from a small subpopulation of transfected cells. We demonstrate that VEGF secretion is linearly correlated to intracellular plasmid copy number and protein secretion does not appear to reach saturation within the cell population. The selection of gene therapy approaches that optimize individual cell secretion profiles may be essential for the development of effective gene therapies.     

乳腺癌干细胞和乳腺癌

肿瘤干细胞既包含干细胞的特性也包含肿瘤细胞的特性。乳腺癌起源于乳腺癌干细胞的说法能够合理地解释乳腺癌的不均一性及其治疗后的复发,这些变异的干细胞可能作为肿瘤预防策略的靶标。而且,由于乳腺癌干细胞能够抵抗辐射治疗和化学治疗,所以要想更好地治疗乳腺癌就需要寻找针对这些干细胞的靶标。我们综述了乳腺癌干细胞的发现、富集和分离、相关的信号途径,以及在乳腺癌治疗中的应用。     

Management of externally manufactured cell therapy products: the Mayo Clinic approach

BackgroundThe rise of investigative and commercially available cell therapy products adds a new dynamic to academic medical centers; that is, the management of patient-specific cell products. The scope of cell therapy has rapidly expanded beyond in-house collection and infusion of cell products such as bone marrow and peripheral blood transplant. The complexities and volumes of cell therapies are likely to continue to become more demanding. As patient-specific “living drugs,” cell therapy products typically require material collection, product provenance, transportation and maintenance of critical quality attributes, including temperature and expiration dates. These requirements are complicated by variations in product-specific attributes, reporting requirements and interactions with industry not required of typical pharmaceuticals.MethodsTo manage these requirements, the authors set out to establish a framework within the Immune, Progenitor and Cell Therapeutics Lab, the Current Good Manufacturing Practice facility responsible for cell manufacturing at Mayo Clinic Rochester housed within the Division of Transfusion Medicine. The authors created a work unit (biopharmaceutical unit) dedicated to addressing the specialized procedures required to properly handle these living drugs from collection to delivery and housing the necessary processes to more easily integrate externally manufactured cell therapies into clinical practice.ResultsThe result is a clear set of expectations defined for each step of the process, with logical documentation of critical steps that are concise and easy to follow.ConclusionsThe authors believe this system is scalable for addressing the promised growth of cell therapy products well into the future. Here the authors describe this system and provide a framework that could be used by other centers to manage these important new therapies.     

Renal stem cell reprogramming: Prospects in regenerative medicine

Stem cell therapy is a promising future enterprise for renal replacement in patients with acute and chronic kidney disease, conditions which affect millions worldwide and currently require patients to undergo lifelong medical treatments through dialysis and/or organ transplant. Reprogramming differentiated renal cells harvested from the patient back into a pluripotent state would decrease the risk of tissue rejection and provide a virtually unlimited supply of cells for regenerative medicine treatments, making it an exciting area of current research in nephrology. Among the major hurdles that need to be overcome before stem cell therapy for the kidney can be applied in a clinical setting are ensuring the fidelity and relative safety of the reprogrammed cells, as well as achieving feasible efficiency in the reprogramming processes that are utilized. Further, improved knowledge about the genetic control of renal lineage development is vital to identifying predictable and efficient reprogramming approaches, such as the expression of key modulators or the regulation of geneactivity through small molecule mimetics. Here, we discuss several recent advances in induced pluripotent stem cell technologies. We also explore strategies that have been successful in renal progenitor generation, and explore what these methods might mean for the development of cell-based regenerative therapies for kidney disease.     

Design and development of a new ambr250® bioreactor vessel for improved cell and gene therapy applications

The emergence of cell and gene therapies has generated significant interest in their clinical and commercial potential. However, these therapies are prohibitively expensive to manufacture and can require extensive time for development due to our limited process knowledge and understanding. The automated ambr250® stirred-tank bioreactor platform provides an effective platform for high-throughput process development. However, the original dual pitched-blade 20 mm impeller and baffles proved sub-optimal for cell therapy candidates that require suspension of microcarriers (e.g. for the culture of adherent human mesenchymal stem cells) or other particles such as activating Dynabeads® (e.g. for the culture of human T-cells). We demonstrate the development of a new ambr250® stirred-tank bioreactor vessel which has been designed specifically to improve the suspension of microcarriers/beads and thereby improve the culture of such cellular systems. The new design is unbaffled and has a single, larger elephant ear impeller. We undertook a range of engineering and physical characterizations to determine which vessel and impeller configuration would be most suitable for suspension based on the minimum agitation speed (N_JS) and associated specific power input (P/V)_JS. A vessel (diameter, T, = 60 mm) without baffles and incorporating a single elephant ear impeller (diameter 30 mm and 45° pitch-blade angle) was selected as it had the lowest (P/V)_JS and therefore potentially, based on Kolmogorov concepts, was the most flexible system. These experimentally-based conclusions were further validated firstly with computational fluid dynamic (CFD) simulations and secondly experimental studies involving the culture of both T-cells with Dynabeads® and hMSCs on microcarriers. The new ambr250® stirred-tank bioreactor successfully supported the culture of both cell types, with the T-cell culture demonstrating significant improvements compared to the original ambr250® and the hMSC-microcarrier culture gave significantly higher yields compared with spinner flask cultures. The new ambr250® bioreactor vessel design is an effective process development tool for cell and gene therapy candidates and potentially for autologous manufacture too.

     

Haematopoietic stem cell niches: new insights inspire new questions

Haematopoietic stem cell (HSC) niches provide an environment essential for life‐long HSC function. Intense investigation of HSC niches both feed off and drive technology development to increase our capability to assay functionally defined cells with high resolution. A major driving force behind the desire to understand the basic biology of HSC niches is the clear implications for clinical therapies. Here, with particular emphasis on cell type‐specific deletion of SCL and CXCL12, we focus on unresolved issues on HSC niches, framed around some very recent advances and novel discoveries on the extrinsic regulation of HSC maintenance. We also provide ideas for possible paths forward, some of which are clearly within reach while others will require both novel tools and vision.     

全球免疫细胞治疗药物开发现状与趋势

目的:从产品开发角度分析免疫细胞治疗类药物的发展现状和未来趋势。方法:检索科睿唯安(Clarivate Analytics)的Cortellis数据库的数据,利用定量分析法和对比分析法对检索结果进行分析。结果:目前已有2种免疫细胞治疗类药物上市,1种免疫细胞治疗类药物处于预注册阶段,4种药物处于临床Ⅲ期,同时大量处于临床Ⅱ/Ⅰ期药物显示未来市场上将有更多免疫细胞治疗类药物。产品交易方面,目前在免疫细胞治疗类药物的商业交易也趋向频繁。通过列举分析目前已发生的交易金额前十的交易,发现其中药物开发及商业化许可是最主要的交易模式。结论:目前免疫细胞治疗类药物市场尚处于起步阶段,但随着未来技术的不断发展改进,相信未来有更多的药物进入商用市场,为癌症及其他疾病的治疗提供新的契机。     

Neuronal ceroid lipofuscinoses therapeutic strategies: past, present and future

Historically, many different therapies have been assessed for their ability to alter disease progression of the Neuronal Ceroid Lipofuscinoses (NCLs). While some treatments have lead to minor improvements, none have been able to arrest disease progression or improve the quality or duration of life. Presently, many new therapeutic strategies, such as chaperone therapy, enzyme replacement therapy, gene therapy, and stem cell therapy, are being investigated for their ability to alter the disease course of the NCLs. This review summarizes previous studied therapies, discusses those currently being evaluated and examines possibilities for future therapies for the treatment of patients with NCL.     

Making efficient use of patients in designing phase III trials investigating simultaneously a set of targeted therapies with different targets

Targeted therapies are a recent development in cancer treatment research. As these therapies can only be administered to patients with certain individual characteristics, it is a straightforward idea to investigate several of such therapies simultaneously in a given patient population in order to compare each targeted therapy with the current standard therapy. This raises the question how patients satisfying several characteristics should be handled. We consider in this paper several designs to allocate treatments in a random manner to these patients, such that the evaluation of each single targeted therapy can be based on a simple comparison of patients receiving the targeted therapies versus those receiving the standard therapy within a well defined subgroup of patients satisfying the corresponding characteristic. We show how one can ensure that patients with several characteristics can contribute simultaneously to the evaluation of several targeted therapies and that this is the key point for an efficient use of the patients available. We further discuss some ethical and practical issues in applying the new designs and outline strategies to evaluate the overall effect of all targeted therapies together.     

Accelerating the development of innovative cellular therapy products for the treatment of cancer

The field of cell therapy is rapidly emerging as a priority area for oncology research and drug development. Currently, two chimeric antigen receptor T-cell therapies are approved by the US Food and Drug Administration and other agencies worldwide for two types of hematologic cancers. To facilitate the development of these therapies for patients with life-threatening cancers with limited or no therapeutic options, science- and risk-based approaches will be critical to mitigating and balancing any potential risk associated with either early clinical research or more flexible manufacturing paradigms. Friends of Cancer Research and the Parker Institute for Cancer Immunotherapy convened an expert group of stakeholders to develop specific strategies and proposals for regulatory opportunities to accelerate the development of cell therapies as promising new therapeutics. This meeting took place in Washington, DC on May 17, 2019. As academia and industry expand research efforts and cellular product development pipelines, this report summarizes opportunities to accelerate entry into the clinic for exploratory studies and optimization of cell products through manufacturing improvements for these promising new therapies.     

A risk-based approach for cell line development,manufacturing and characterization of genetically engineered,induced pluripotent stem cell–derived allogeneic cell therapies

Advances in cellular reprogramming and gene-editing approaches have opened up the potential for a new class of ex vivo cell therapies based on genetically engineered, induced pluripotent stem cell (iPSC)-derived allogeneic cells. While these new therapies share some similarities with their primary cell-derived autologous and allogeneic cell therapy predecessors, key differences exist in the processes used for generating genetically engineered, iPSC-derived allogeneic therapies. Specifically, in iPSC-derived allogeneic therapies, donor selection and gene-editing are performed once over the lifetime of the product as opposed to as part of the manufacturing of each product batch. The introduction of a well-characterized, fully modified, clonally derived master cell bank reduces risks that have been inherent to primary-cell derived autologous and allogeneic therapies. Current regulatory guidance, which was largely developed based on the learnings gained from earlier generation therapies, leaves open questions around considerations for donor eligibility, starting materials and critical components, cell banking and genetic stability. Here, a risk-based approach is proposed to address these considerations, while regulatory guidance continues to evolve.     

Hemangiomas - current therapeutic strategies

Hemangiomas are benign neoplasms of the vasculature frequently encountered in children. Several studies have shown that these tumors are characterized by excessive angiogenesis. Although benign, the lesions can present with complications, and may thus require treatment. There are multiple therapeutic options available for patients with problematic or life threatening hemangiomas, some of which have serious side effects. Randomized clinical trials and evidence-based studies on the efficacy of these treatments is still lacking. The recognition that excessive angiogenesis underlies hemangiogenesis offers an opportunity for the development of safer therapeutic strategies that are based on the inhibition of angiogenesis. We review medical therapies currently employed in the management of hemangiomas and the role of angiogenesis inhibition in hemangioma therapy.     

Immunotherapy in the treatment of lymphoma

Relapsed or refractory non-Hodgkin's lymphomas, especially diffuse large B-cell lymphoma as well as relapsed or refractory Hodgkin lymphomas are hard-to-treat diseases. Patients who do not respond to initial therapy or experience relapse are treated with salvage regimens, and if eligible for aggressive therapy, treatment is continued with high-dose chemotherapy and autologous stem cell transplantation. Current therapy options can cure substantial numbers of patients, however for some it is still an uncurable disease. Numerous new drugs and cell therapies are being investigated for the treatment of relapsed or refractory lymphomas. Different types of immunotherapy options have shown promising results, and some have already become the standard of care. Here, we review immunotherapy options for the treatment of lymphoma and discuss the results, positions, practical aspects, and future directions of different drugs and cellular therapies for the treatment of this disease.