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  • The advantages of CP could be even

    2018-11-06

    The advantages of CP could be even more profound for manufacturing cell therapies. In a typical cell therapy workflow, hPSCs are expanded and banked in a GMP facility before undergoing expensive and time-consuming tests to validate the cell bank. The conversion of this PSC bank into a therapeutically useful cell type usually requires recovery from the cryopreserved state and a limited number of cell passages before initiating differentiation into the therapeutic cell type. This creates the possibility of initiating the differentiation of a cell bank with PSCs in a suboptimal state, potentially limiting reproducibility and product yield. Manufacturing runs can be exorbitantly expensive in time and money and could potentially cause adverse events in patients. Reproducibility of manufacturing is also one of the key attributes that regulatory authorities examine when assessing a cellular product\'s safety for human use. Our laboratory recently led the manufacture of a clinically compatible midbrain dopamine neuron product (MSK-DA01) intended for a phase 1 clinical trial after investigational new drug-enabling studies that are currently ongoing (Lorenz Studer\'s NYSTEM consortium group; Barker et al., 2015). Four at-scale batches of our product were manufactured, and while all met release criteria, the PSC expansion caused challenges in the timing of production and limited scale during particular runs due to the variable yield and timing during expansion. Timing, yield, and quality of PSC expansion can be completely eliminated as variables for cell therapies if CP can be validated for such applications. We show here that CP WA09 aa-dutp can be directed to midbrain dopamine neurons using our clinically compatible SOP, but more work is needed before advancing this method to the clinic. If validated, there seems little doubt that manufacturing cell therapies from PSCs will become more robust and reproducible. CP will also be invaluable for “process development,” the systematic exploration of “cleaner” components needed to differentiate cells for clinical use.
    Experimental Procedures
    Author Contributions
    Acknowledgments New York State\'s stem cell funding agency (NYSTEM) has been essential for this work and our laboratory. Contract C029153 (M.J.T., PI) has helped fund the basic operation of our facility and allowed us to develop CryoPause. Contract C028503 allowed us to manufacture a hESC-based therapy described in the manuscript (Lorenz Studer, PI). The authors also wish to acknowledge the tremendous contributions of The Starr Foundation for our initial seed funding and for their ongoing support. The authors thank Gouri Nanjangud and staff at the Molecular Cytogenetics Core, and Agnes Viale, Juan Li, Kety Huberman, and their staff at the Integrated Genomics Operation at MSKCC. Both cores provide outstanding service and support, and are supported by the NCI Cancer Center Support grant P30 CA008748. The Integrated Genomics Operation is also supported by Cycle for Survival and the Marie-Josée and Henry R. Kravis Center for Molecular Oncology. F.J.M. was supported by grants from the BMBF (13GW0128A and 01GM1513D) and from the Deutsche Forschungsgemeinschaft (DFG MU 3231/3-1). C.Z. and D.B. are supported by Tri-Institutional Research Programs (grant no. 2013-036). We also thank Danwei Huangfu and her entire laboratory (MSKCC) for always sharing reagents and expertise with us, including the iCRISPR WA01 line used here.
    Introduction Human embryonic stem cells (hESCs), after directed differentiation, are valuable in regenerative medicine. However, clinical trials using hESC-derived cells remain scarce primarily because hESC lines available worldwide are mostly of nonclinical grade. To generate clinical-grade cells, good manufacturing practices (GMPs), which cover operating procedures and product quality control, must be employed (Ausubel et al., 2011). GMP is a quality assurance system that requires the traceability of materials and the validation of standard operating procedures (SOPs) (Unger et al., 2008). Stem cells are a type of human cellular and tissue-based product (HCT/P). In many countries, HCT/Ps are regulated under guidelines such as 21 CFR 1270 and 21 CFR 1271 issued by the US Food and Drug Administration (FDA) (FDA, 2012). Stem cell-based products must also meet the requirements of other therapeutic products including drugs, medical devices, xeno-transplants, and biological products (Fink, 2009). Therefore, a number of countries and professional associations (e.g., International Society for Stem Cell Research) have issued preliminary regulatory policies for the clinical application of stem cells, and GMP serves as the basic requirement for the generation of clinical-grade hESCs (Fink, 2009; Hyun et al., 2008; Wilkerson et al., 2013). The existing guidelines incorporate guidelines produced by the British Standards Institute for cell-based clinical application (Ratcliffe et al., 2013). Recently, in China, drafts of a stem cell-specific clinical therapy quality control standard and management of stem cell-based clinical experiments were implemented by the China Food and Drug Administration (CFDA) (http://www.sda.gov.cn) and National Health and Family Planning Commission of the People’s Republic of China (NHFPC) (http://www.nhfpc.gov.cn/). Each of these guidelines focuses on the efficacy, safety, and pharmaceutical quality, which are influenced by the cell sources, manufacturing systems, and specific therapeutic protocols (George, 2011; Huang and Fu, 2014). In addition to validating the biosafety of the hESCs, the CFDA and FDA both require rigorous testing of the donors\' eligibility, thus differentiating these guidelines from the present NIH guidelines on human stem cell research (George, 2011; Huang and Fu, 2014; Jonlin, 2014).