GMP-Grade Manufacturing and Quality Control of a Non-Virally Engineered Advanced Therapy Medicinal Product for Personalized Treatment of Age-Related Macular Degeneration

Academic challenges on advanced therapy medicinal products' development: a regulatory perspective

Advanced therapy medicinal products (ATMPs) are becoming the new kid on the block for the treatment of a variety of indications with promising results. Despite the academic contribution to the basic and clinical research of ATMPs, undertaking a full product development process is extraordinarily challenging and demanding for academic institutions. Meeting regulatory requirements is probably the most challenging aspect of academic development, considering the limited experience and resources compared with pharmaceutical companies. This review aims to outline the key aspects to be considered when developing novel ATMPs from an academic perspective, based on the results of our own experience and interaction with the Spanish Agency of Medicines and Medical Devices (AEMPS) and European Medicine Agency (EMA) related to a number of academic ATMP initiatives carried out at our center during the last 5 years. Emphasis is placed on understanding the regulatory requirements during the early phases of the drug development process, particularly for the preparation of a Clinical Trial Application. Academic centers usually lack expertise in product-related documentation (such as the Investigational Medicinal Product Dossier), and therefore, early interaction with regulators is crucial to understand their requirements and receive guidance to comply with them. Insights are shared on managing quality, nonclinical, clinical, and risk and benefit documentation, based on our own experience and challenges. This review aims to empower academic and clinical settings by providing crucial regulatory knowledge to smooth the regulatory journey of ATMPs.

Antibiotic-Free Gene Vectors: A 25-Year Journey to Clinical Trials

Until very recently, the major use, for gene therapy, specifically of linear or circular DNA, such as plasmids, was as ancillary products for viral vectors' production or as a genetic template for mRNA production. Thanks to targeted and more efficient physical or chemical delivery techniques and to the refinement of their structure, non-viral plasmid DNA are now under intensive consideration as pharmaceutical drugs. Plasmids traditionally carry an antibiotic resistance gene for providing the selection pressure necessary for maintenance in a bacterial host. Nearly a dozen different antibiotic-free gene vectors have now been developed and are currently assessed in preclinical assays and phase I/II clinical trials. Their reduced size leads to increased transfection efficiency and prolonged transgene expression. In addition, associating non-viral gene vectors and DNA transposons, which mediate transgene integration into the host genome, circumvents plasmid dilution in dividing eukaryotic cells which generate a loss of the therapeutic gene. Combining these novel molecular tools allowed a significantly higher yield of genetically engineered T and Natural Killer cells for adoptive immunotherapies due to a reduced cytotoxicity and increased transposition rate. This review describes the main progresses accomplished for safer, more efficient and cost-effective gene and cell therapies using non-viral approaches and antibiotic-free gene vectors.

Evaluating Ecological Impact and Sustainability in the Manufacturing of Advanced Therapies: Comparative Analysis of Greenhouse Gas Emissions in the Production of ATMPs in Open and Closed Systems

The primary aim of this systematic analysis is to highlight opportunities to improve the environmental impact of advanced therapy medicinal products (ATMP) manufacturing. We have compared the Greenhouse Gas (GHG) emissions expressed in CO2eq of a classic clean room open system (AinB) Cell Factory versus a comparable closed system equipped with isolators (AinD). We have therefore outlined a theoretical situation to simulate the use of a closed system with an equivalent production output to that obtained in the Cell Factory (CF) of the Regina Margherita Children's Hospital. Open and closed systems for ATMPs have been compared as regards energy requirements, ecological footprints, and costs by analyzing a hypothetic cell production cycle of 21 days. The results demonstrate energy saving and a reduction of 52% in GHG emissions using closed systems per process cycle. Moreover, a reduction in production costs in an isolator setting is also evident. This study shows that the closed system solution has evident advantages compared with the open one.

Mammalian Animal and Human Retinal Organ Culture as Pre-Clinical Model to Evaluate Oxidative Stress and Antioxidant Intraocular Therapeutics

Oxidative stress (OS) is involved in the pathogenesis of retinal neurodegenerative diseases such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) and an important target of therapeutic treatments. New therapeutics are tested in vivo despite limits in terms of transferability and ethical concerns. Retina cultures using human tissue can deliver critical information and significantly reduce the number of animal experiments along with increased transferability. We cultured up to 32 retina samples derived from one eye, analyzed the model's quality, induced OS, and tested the efficiency of antioxidative therapeutics. Bovine, porcine, rat, and human retinae were cultured in different experimental settings for 3-14 d. OS was induced by a high amount of glucose or hydrogen peroxide (H₂O₂) and treated with scutellarin, pigment epithelium-derived factor (PEDF), and/or granulocyte macrophage colony-stimulating factor (GM-CSF). The tissue morphology, cell viability, inflammation, and glutathione level were determined. The retina samples showed only moderate necrosis (23.83 ± 5.05 increased to 27.00 ± 1.66 AU PI-staining over 14 d) after 14 days in culture. OS was successfully induced (reduced ATP content of 288.3 ± 59.9 vs. 435.7 ± 166.8 nM ATP in the controls) and the antioxidants reduced OS-induced apoptosis (from 124.20 ± 51.09 to 60.80 ± 319.66 cells/image after the scutellarin treatment). Enhanced mammalian animal and human retina cultures enable reliable, highly transferable research on OS-triggered age-related diseases and pre-clinical testing during drug development.

Enhanced Biosafety of the Sleeping Beauty Transposon System by Using mRNA as Source of Transposase to Efficiently and Stably Transfect Retinal Pigment Epithelial Cells

Neovascular age-related macular degeneration (nvAMD) is characterized by choroidal neovascularization (CNV), which leads to retinal pigment epithelial (RPE) cell and photoreceptor degeneration and blindness if untreated. Since blood vessel growth is mediated by endothelial cell growth factors, including vascular endothelial growth factor (VEGF), treatment consists of repeated, often monthly, intravitreal injections of anti-angiogenic biopharmaceuticals. Frequent injections are costly and present logistic difficulties; therefore, our laboratories are developing a cell-based gene therapy based on autologous RPE cells transfected ex vivo with the pigment epithelium derived factor (PEDF), which is the most potent natural antagonist of VEGF. Gene delivery and long-term expression of the transgene are enabled by the use of the non-viral Sleeping Beauty (SB100X) transposon system that is introduced into the cells by electroporation. The transposase may have a cytotoxic effect and a low risk of remobilization of the transposon if supplied in the form of DNA. Here, we investigated the use of the SB100X transposase delivered as mRNA and showed that ARPE-19 cells as well as primary human RPE cells were successfully transfected with the Venus or the PEDF gene, followed by stable transgene expression. In human RPE cells, secretion of recombinant PEDF could be detected in cell culture up to one year. Non-viral ex vivo transfection using SB100X-mRNA in combination with electroporation increases the biosafety of our gene therapeutic approach to treat nvAMD while ensuring high transfection efficiency and long-term transgene expression in RPE cells.