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Abstract A significant portion of the more than 1000 candidate cell and gene therapy products currently under clinical investigation (clinicaltrials.gov) are born out of academic research centers affiliated with universities, hospitals and non-profit research institutions. Supporting these efforts are myriad academic clinical materials production facilities with more than 40 such facilities currently operational in the United States alone. In March 2018, Stanford University's Laboratory for Cell and Gene Therapy held a symposium with the leaders and staff of more than 25 similar facilities to discuss the collective experience in developing, qualifying and operating cell and gene therapy manufacturing facilities according to current Good Manufacturing Practices. Topics included facility design, construction, staffing and operations and compliance. Leaders from several institutions gave overviews of the history of development of the facilities and discussed challenges and opportunities they had experienced over the past 10–20 years of operations. Working sessions were also held to discuss specific aspects of Process Development, Manufacturing, Quality Systems, Regulatory Affairs and Business Development with all participants contributing to the discussions. We summarize here the findings of this inaugural meeting with an emphasis on best practices and suggested guidelines for operations. [ABSTRACT FROM AUTHOR]

Over the past 15 years we have been investigating an alternative approach to treating HIV-1/AIDS, based on the creation of a disease-resistant immune system through transplantation of autologous, gene-modified (HIV-1-resistant) hematopoietic stem and progenitor cells (GM-HSPC). We propose that the expression of selected RNA-based HIV-1 inhibitors in the CD4+ cells derived from GM-HSPC will protect them from HIV-1 infection and results in a sufficient immune repertoire to control HIV-1 viremia resulting in a functional cure for HIV-1/AIDS. Additionally, it is possible that the subset of protected T cells will also be able to facilitate the immune-based elimination of latently infected cells if they can be activated to express viral antigens. Thus, a single dose of disease resistant GM-HSPC could provide an effective treatment for HIV-1+ patients who require (or desire) an alternative to lifelong antiretroviral chemotherapy. We describe herein the results from several pilot clinical studies in HIV-1 patients and our strategies to develop second generation vectors and clinical strategies for HIV-1+ patients with malignancy who require ablative chemotherapy as part of treatment and others without malignancy. The important issues related to stem cell source, patient selection, conditioning regimen and post-infusion correlative studies become increasingly complex and are discussed herein. [ABSTRACT FROM AUTHOR]

Clinical trials over the last 15 years have demonstrated that cell and gene therapies for cancer, monogenic and infectious disease are feasible and can lead to long-term benefit for patients. However, these trials have been limited to proof-of-principle and were conducted on modest numbers of patients or over long periods of time. In order for these studies to move towards standard practice and commercialization, scalable technologies for the isolation, ex vivo manipulation and delivery of these cells to patients must be developed. Additionally, regulatory strategies and clinical protocols for the collection, creation and delivery of cell products must be generated. In this article we review recent progress in hematopoietic cell and gene therapy, describe some of the current issues facing the field and discuss clinical, technical and regulatory approaches used to navigate the road to product development. [ABSTRACT FROM AUTHOR]

Metastatic neuroblastoma is a poor-prognosis malignancy arising during childhood that overexpresses the L1-cell adhesion molecule (CD171). We have previously described a tumor L1-cell adhesion molecule-specific, single chain antibody-derived, chimeric antigen receptor designated CE7R for re-directing the antigen-specific effector functioning of cytolytic T lymphocytes. Here, we report on the feasibility of isolating, and the safety of infusing, autologous CD8+ cytolytic T lymphocyte clones co-expressing CE7R and the selection-suicide expression enzyme HyTK in children with recurrent/refractory neuroblastoma. The cytolytic T lymphocyte products were derived from peripheral blood mononuclear cells that were subjected to polyclonal activation, plasmid vector electrotransfer, limiting dilution hygromycin selection, and expansion to numbers sufficient for adoptive transfer. In total, 12 infusions (nine at 108 cells/m2, three at 109 cells/m2) were administered to six patients. No overt toxicities to tissues known to express L1-cell adhesion molecule (e.g., central nervous system, adrenal medulla, and sympathetic ganglia) were observed. The persistence of cytolytic T lymphocyte clones in the circulation, measured by vector-specific quantitative polymerase chain reaction, was short (1-7 days) in patients with bulky disease, but significantly longer (42 days) in a patient with a limited disease burden. This first-in-humans pilot study sets the stage for clinical trials employing adoptive transfer in the context of minimal residual disease.Molecular Therapy (2007) 15 4, 825–833 doi:10.1038/sj.mt.6300104 [ABSTRACT FROM AUTHOR]

Gene therapy with hematopoietic stem and progenitor cells is a promising approach to engineering immunity to human immunodeficiency virus (HIV) that may lead to a functional cure for acquired immunodeficiency syndrome (AIDS). In support of this approach, we created lentiviral vectors with an engineered polycistronic platform derived from the endogenous MCM7 gene to express a diverse set of small antiviral RNAs and a drug resistance MGMTP140K marker. Multiple strategies for simultaneous expression of up to five RNA transgenes were tested. The placement and orientation of each transgene and its promoter were important determinants for optimal gene expression. Antiviral RNA expression from the MCM7 platform with a U1 promoter was sufficient to provide protection from R5-tropic HIV in macrophages and resulted in reduced hematopoietic toxicity compared with constructs expressing RNA from independent RNA polymerase III promoters. The addition of an HIV entry inhibitor and nucleolar TAR RNA decoy did not enhance antiviral potency over constructs that targeted only viral RNA transcripts. We also demonstrated selective enrichment of gene-modified cells in vivo using a humanized mouse model. The use of these less toxic, potent anti-HIV vectors expressing a drug selection marker is likely to enhance the in vivo efficacy of our stem cell gene therapy approach in treating HIV/AIDS. [ABSTRACT FROM AUTHOR]

The HIV-1 coreceptor CCR5 is a validated target for HIV/AIDS therapy. The apparent elimination of HIV-1 in a patient treated with an allogeneic stem cell transplant homozygous for a naturally occurring CCR5 deletion mutation (CCR5Δ32/Δ32) supports the concept that a single dose of HIV-resistant hematopoietic stem cells can provide disease protection. Given the low frequency of naturally occurring CCR5Δ32/Δ32 donors, we reasoned that engineered autologous CD34+ hematopoietic stem/progenitor cells (HSPCs) could be used for AIDS therapy. We evaluated disruption of CCR5 gene expression in HSPCs isolated from granulocyte colony-stimulating factor (CSF)-mobilized adult blood using a recombinant adenoviral vector encoding a CCR5-specific pair of zinc finger nucleases (CCR5-ZFN). Our results demonstrate that CCR5-ZFN RNA and protein expression from the adenoviral vector is enhanced by pretreatment of HSPC with protein kinase C (PKC) activators resulting in >25% CCR5 gene disruption and that activation of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway is responsible for this activity. Importantly, using an optimized dose of PKC activator and adenoviral vector we could generate CCR5-modified HSPCs which engraft in a humanized mouse model (albeit at a reduced level) and support multilineage differentiation in vitro and in vivo. Together, these data establish the basis for improved approaches exploiting adenoviral vector delivery in the modification of HSPCs. [ABSTRACT FROM AUTHOR]

AbstractCombinational therapy with small RNA inhibitory agents against multiple viral targets allows efficient inhibition of viral production by controlling gene expression at critical time points. Here we explore combinations of different classes of therapeutic anti-HIV-1 RNAs expressed from within the context of an intronic MCM7 (minichromosome maintenance complex component-7) platform that naturally harbors 3 microRNAs (miRNAs). We replaced the endogenous miRNAs with anti-HIV small RNAs, including small interfering RNAs (siRNAs) targeting HIV-1 tatand revmessages that function to induce post-transcriptional gene silencing by the RNA interference pathway, a nucleolar-localizing RNA ribozyme that targets the conserved U5 region of HIV-1 transcripts for degradation, and finally nucleolar trans-activation response (TAR) and Rev-binding element (RBE) RNA decoys designed to sequester HIV-1 Tat and Rev proteins inside the nucleolus. We demonstrate the versatility of the MCM7 platform in expressing and efficiently processing the siRNAs as miRNA mimics along with nucleolar small RNAs. Furthermore, three of the combinatorial constructs tested potently suppressed viral replication during a 1-month HIV challenge, with greater than 5-log inhibition compared with untransduced, HIV-1-infected CEM T lymphocytes. One of the most effective constructs contains an anti-HIV siRNA combined with a nucleolar-localizing U5 ribozyme and TAR decoy. This represents the first efficacious example of combining Drosha-processed siRNAs with small nucleolar ribonucleoprotein (snoRNP)-processed nucleolar RNA chimeras from a single intron platform for effective inhibition of viral replication. Moreover, we demonstrated enrichment/selection for cells expressing levels of the antiviral RNAs that provide optimal inhibition under the selective pressure of HIV. The combinations of si/snoRNAs represent a new paradigm for combinatorial RNA-based gene therapy applications. [ABSTRACT FROM AUTHOR]