Regulatory Considerations for Genome-Edited T-cell Therapies.

Methods to engineer the genomes of human cells for therapeutic intervention continue to advance at a remarkable pace. Chimeric antigen receptor-engineered T lymphocytes have pioneered the way for these therapies, initially beginning with insertions of chimeric antigen receptor transgenes into T-cell genomes using classical gene therapy vectors. The broad use of clustered regularly interspaced short palindromic repeats (CRISPR)-based technologies to edit endogenous genes has now opened the door to a new era of precision medicine. To add complexity, many engineered cellular therapies under development integrate gene therapy with genome editing to introduce novel biological functions and enhance therapeutic efficacy. Here, we review the current state of scientific, translational, and regulatory oversight of gene-edited cell products.

Improving the Assessment of Risk Factors Relevant to Potential Carcinogenicity of Gene Therapies: A Consensus Article.

Regulators and industry are actively seeking improvements and alternatives to current models and approaches to evaluate potential carcinogenicity of gene therapies (GTs). A meeting of invited experts was organized by NC3Rs/UKEMS (London, March 2023) to discuss this topic. This article describes the consensus reached among delegates on the definition of vector genotoxicity, sources of uncertainty, suitable toxicological endpoints for genotoxic assessment of GTs, and future research needs. The collected recommendations should inform the further development of regulatory guidelines for the nonclinical toxicological assessment of GT products.

Contract development and manufacturing organization selection: critical considerations that can make or break your cell and gene therapy development.

BACKGROUND AIMS: With the increase in cell and gene therapy (CGT) clinical trials in recent years has come a subsequent increase in the number of contract development and manufacturing organizations (CDMOs). Successful transition from development and early-phase clinical trials to commercialization of a CGT product often depends on selecting the best-suited CDMO. However, many CGT companies are small biotech companies that lack expertise in the field or do not have experience selecting and transferring a process to a CDMO. METHODS: Given the interest in this topic, a roundtable with CGT developers and CDMO members at the 2023 annual meeting of the International Society of Cell and Gene Therapy Paris discussed these critical aspects of product development, including technical expertise, risk sharing and timing of partnerships. RESULTS AND CONCLUSIONS: Here, we'll analyze the considerations discussed by the panel and elaborate on other factors crucial for CGT development.

T cell lymphoma and secondary primary malignancy risk after commercial CAR T cell therapy.

We report a T cell lymphoma (TCL) occurring 3 months after anti-CD19 chimeric antigen receptor (CAR) T cell immunotherapy for non-Hodgkin B cell lymphoma. The TCL was diagnosed from a thoracic lymph node upon surgery for lung cancer. The TCL exhibited CD8+ cytotoxic phenotype and a JAK3 variant, while the CAR transgene was very low. The T cell clone was identified at low levels in the blood before CAR T infusion and in lung cancer. To assess the overall risk of secondary primary malignancy after commercial CAR T (CD19, BCMA), we analyzed 449 patients treated at the University of Pennsylvania. At a median follow-up of 10.3 months, 16 patients (3.6%) had a secondary primary malignancy. The median onset time was 26.4 and 9.7 months for solid and hematological malignancies, respectively. The projected 5-year cumulative incidence is 15.2% for solid and 2.3% for hematological malignancies. Overall, one case of TCL was observed, suggesting a low risk of TCL after CAR T.

Beyond youth: Understanding CAR T cell fitness in the context of immunological aging.

Population aging, a pervasive global demographic trend, is anticipated to challenge health and social systems worldwide. This phenomenon is due to medical advancements enabling longer lifespans, with 20% of the US population soon to be over 65 years old. Consequently, there will be a surge in age-related diseases. Senescence, characterized by the loss of biological maintenance and homeostasis at molecular and cellular levels, either correlates with or directly causes age-related phenotypic changes. Decline of the immune system is a critical factor in the senescence process, with cancer being a primary cause of death in elderly populations. Chimeric antigen receptor (CAR) T cell therapy, an innovative approach, has demonstrated success mainly in pediatric and young adult hematological malignancies but remains largely ineffective for diseases affecting older populations, such as late-in-life B cell malignancies and most solid tumor indications. This limitation arises because CAR T cell efficacy heavily relies on the fitness of the patient-derived starting T cell material. Numerous studies suggest that T cell senescence may be a key driver of CAR T cell deficiency. This review examines correlates and underlying factors associated with favorable CAR T cell outcomes and explores potential experimental and clinically actionable strategies for T cell rejuvenation.

A simulation-based comparison of centralized and point-of-care supply chain strategies for autologous cell therapy.

BACKGROUND AIMS: The selection between centralized and point-of-care (POC) manufacturing supply-chain network design is a crucial consideration in the autologous cell therapy (AuCT) industry, as each approach offers its advantages and disadvantages. METHODS: This study uses a simulation-based approach to compare and examine the two strategies using the supply chain for chimeric antigen receptor T-cell therapy manufacturing as an exemplar. When does it make sense to use one manufacturing strategy over another? Currently, major manufacturers in the AuCT industry use centralized supply-chain strategies predominantly in practice. The simulation results explain the reasons for this choice. To enhance the competitiveness of the POC strategy, two operation rules are proposed and tested with the simulation. The study uses key performance indicators such as cost, fulfillment time, service level, and resource utilization to provide generic guidelines based on the findings. RESULTS: The results have revealed that (i) the centralized supply-chain strategy has a significant advantage at current demand levels of a few thousand products per year; (ii) "optimal capacity" exists for the POC strategy that minimizes the cost of goods and (iii) allowing part-time labor and order transshipment can significantly increase the competitiveness of the POC strategy. CONCLUSIONS: This study may be useful in helping commercial manufacturers make informed decisions about their manufacturing approach to enhance their competitiveness in the market and to ensure a high level of patient benefit.

A phase 1 trial of adoptive transfer of vaccine-primed autologous circulating T cells in ovarian cancer.

We have previously shown that vaccination with tumor-pulsed dendritic cells amplifies neoantigen recognition in ovarian cancer. Here, in a phase 1 clinical study ( NCT01312376 /UPCC26810) including 19 patients, we show that such responses are further reinvigorated by subsequent adoptive transfer of vaccine-primed, ex vivo-expanded autologous peripheral blood T cells. The treatment is safe, and epitope spreading with novel neopeptide reactivities was observed after cell infusion in patients who experienced clinical benefit, suggesting reinvigoration of tumor-sculpting immunity.

International Society for Cell & Gene Therapy Position Paper: Key considerations to support evidence-based cell and gene therapies and oppose marketing of unproven products.

The field of regenerative medicine, including cellular immunotherapies, is on a remarkable growth trajectory. Dozens of cell-, tissue- and gene-based products have received marketing authorization worldwide while hundreds-to-thousands are either in preclinical development or under clinical investigation in phased clinical trials. However, the promise of regenerative therapies has also given rise to a global industry of direct-to-consumer offerings of prematurely commercialized cell and cell-based products with unknown safety and efficacy profiles. Since its inception, the International Society for Cell & Gene Therapy Committee on the Ethics of Cell and Gene Therapy has opposed the premature commercialization of unproven cell- and gene-based interventions and supported the development of evidence-based advanced therapy products. In the present Guide, targeted at International Society for Cell & Gene Therapy members, we analyze this industry, focusing in particular on distinctive features of unproven cell and cell-based products and the use of tokens of scientific legitimacy as persuasive marketing devices. We also provide an overview of reporting mechanisms for patients who believe they have been harmed by administration of unapproved and unproven products and suggest practical strategies to address the direct-to-consumer marketing of such products. Development of this Guide epitomizes our continued support for the ethical and rigorous development of cell and cell-based products with patient safety and therapeutic benefit as guiding principles.

Tissue-resident memory CAR T cells with stem-like characteristics display enhanced efficacy against solid and liquid tumors.

Chimeric antigen receptor (CAR) T cells demonstrate remarkable success in treating hematological malignancies, but their effectiveness in non-hematopoietic cancers remains limited. This study proposes enhancing CAR T cell function and localization in solid tumors by modifying the epigenome governing tissue-residency adaptation and early memory differentiation. We identify that a key factor in human tissue-resident memory CAR T cell (CAR-TRM) formation is activation in the presence of the pleotropic cytokine, transforming growth factor ß (TGF-ß), which enforces a core program of both "stemness" and sustained tissue residency by mediating chromatin remodeling and concurrent transcriptional changes. This approach leads to a practical and clinically actionable in vitro production method for engineering peripheral blood T cells into a large number of "stem-like" CAR-TRM cells resistant to tumor-associated dysfunction, possessing an enhanced ability to accumulate in situ and rapidly eliminate cancer cells for more effective immunotherapy.

Paving the Road for Chimeric Antigen Receptor T Cells: American Society for Transplantation and Cellular Therapy 80/20 Task Force Consensus on Challenges and Solutions to Improving Efficiency of Clinical Center Certification and Maintenance of Operations for Commercially Approved Immune Effector Cell Therapies.

As the number and type of regulatory authority-approved cellular therapies grow, clinical treatment centers face a heavy burden of duplicative documentation around initial qualification, ongoing auditing, and reporting, with overlapping requirements from each manufacturer to ensure safe use of their specific product, which in the United States are stipulated under individual Food and Drug Administration (FDA) Biologic License Applications. The American Society for Transplantation and Cellular Therapy (ASTCT) convened the 80/20 Task Force to consider challenges and potential solutions to these issues. The Task Force proposed that 80% of manufacturers' requirements for onboarding and ongoing operations of commercially available products could be standardized and streamlined. Task Force members interviewed dozens of stakeholders, including clinicians at large academic medical centers already using commercial and investigational immune effector cell (IEC) products, regulators, members of accrediting bodies and professional cellular therapy societies, and manufacturers of IEC therapies for oncologic indications. In November 2021, the Task Force organized and led virtual discussions in a public forum and at a private ASTCT 80/20 Workshop at the online AcCELLerate Forum, a cellular-therapy stakeholders' meeting organized by the ASTCT, National Marrow Donor Program (NMDP), and Center for International Blood and Marrow Transplant Research (CIBMTR). At the workshop, approximately 60 stakeholders worked to identify and prioritize common challenges in onboarding and maintenance of operations at clinical sites for commercial FDA-approved and future IEC therapies and ways to streamline the process. It was agreed that standardization would improve efficiency of onboarding, allowing more cost-effective, sustainable growth of approved IEC therapies at treatment centers, and facilitate wider access while maintaining safety and clinical success. This early but extensive survey of stakeholders resulted in 5 overarching suggestions for both established and emerging treatment centers: (1) eliminate duplication in accreditation and auditing of clinical sites; (2) define expectations for the education about and management of CAR-T therapy toxicities to potentially replace product-specific REMS programs; (3) streamline current REMS education, testing, and data reporting; (4) standardize information technology (IT) platforms supporting enrollment, clinical site-manufacturer communication, and logistics of maintaining chain of identity/chain of custody across multiple transportation steps; and (5) encourage the use of universal nomenclature by cell therapy manufacturers. Future discussions need to engage a broader range of stakeholders, including administrators, pharmacists, nurses, data coordinators, surgeons, pathologists, and those developing promising cellular therapies for solid tumors, as well as teams from smaller academic or community cancer center settings. Continued collaboration with stakeholders outside of clinical sites will include accrediting bodies/auditors, established and emerging cell therapy companies, software developers, professional societies, and the patients who receive these therapies. Active dialog with government regulators remains essential. Such joint efforts are critical as the number of IEC therapies for myriad oncologic and nononcologic indications grows.

Comprehensive Serum Proteome Profiling of Cytokine Release Syndrome and Immune Effector Cell-Associated Neurotoxicity Syndrome Patients with B-Cell ALL Receiving CAR T19.

PURPOSE: To study the biology and identify markers of severe cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) in children after chimeric antigen receptor T-cell (CAR T) treatment. EXPERIMENTAL DESIGN: We used comprehensive proteomic profiling to measure over 1,400 serum proteins at multiple serial timepoints in a cohort of patients with B-cell acute lymphoblastic leukemia treated with the CD19-targeted CAR T CTL019 on two clinical trials. RESULTS: We identified fms-like tyrosine kinase 3 (FLT3) and mast cell immunoglobulin-like receptor 1 (MILR1) as preinfusion predictive biomarkers of severe CRS. We demonstrated that CRS is an IFNγ-driven process with a protein signature overlapping with hemophagocytic lymphohistiocytosis (HLH). We identified IL18 as a potentially targetable cytokine associated with the development of ICANS. CONCLUSIONS: We identified preinfusion biomarkers that can be used to predict severe CRS with a sensitivity, specificity, and accuracy superior to the current gold standard of disease burden. We demonstrated the fundamental role of the IFNγ pathway in driving CRS, suggesting CRS and carHLH are overlapping rather than distinct phenomena, an observation with important treatment implications. We identified IL18 as a possible targetable cytokine in ICANS, providing rationale for IL18 blocking therapies to be translated into clinical trials in ICANS.

Predicting T-cell quality during manufacturing through an artificial intelligence-based integrative multiomics analytical platform.

Large-scale, reproducible manufacturing of therapeutic cells with consistently high quality is vital for translation to clinically effective and widely accessible cell therapies. However, the biological and logistical complexity of manufacturing a living product, including challenges associated with their inherent variability and uncertainties of process parameters, currently make it difficult to achieve predictable cell-product quality. Using a degradable microscaffold-based T-cell process, we developed an artificial intelligence (AI)-driven experimental-computational platform to identify a set of critical process parameters and critical quality attributes from heterogeneous, high-dimensional, time-dependent multiomics data, measurable during early stages of manufacturing and predictive of end-of-manufacturing product quality. Sequential, design-of-experiment-based studies, coupled with an agnostic machine-learning framework, were used to extract feature combinations from early in-culture media assessment that were highly predictive of the end-product CD4/CD8 ratio and total live CD4+ and CD8+ naïve and central memory T cells (CD63L+CCR7+). Our results demonstrate a broadly applicable platform tool to predict end-product quality and composition from early time point in-process measurements during therapeutic cell manufacturing.

Patient access to and ethical considerations of the application of the European Union hospital exemption rule for advanced therapy medicinal products.

Hospital exemption (HE) is a regulated pathway that allows the use of advanced therapy medicinal products (ATMPs) within the European Union (EU) under restrictive conditions overseen by national medicine agencies. In some EU countries, HE is granted for ATMPs with no demonstrated safety and efficacy; therefore, they are equivalent to investigational drugs. In other countries, HE is granted for ATMPs with demonstrated quality, safety and efficacy and for which centralized marketing authorization has not been requested. The Committee on the Ethics of Cell and Gene Therapy of the International Society for Cell & Gene Therapy reflects here on the ethical issues concerning HE application from the perspective of the patient, including risk-benefit balance, accessibility and transparency, while providing evidence that HE must not be regarded as a conduit for unproven and unethical ATMP-based interventions. Indeed, HE represents a legal instrument under which a patient's need for access to novel ATMPs is reconciled with ethics. Moreover, for some unmet medical needs, HE is the only pathway for accessing innovative ATMPs. Nonetheless, HE harmonization across EU Member States and limitations of ATMP use under the HE rule when similar products have already been granted centralized marketing authorization to avoid a parallel regulatory pathway are controversial issues whose political and economic consequences are beyond the scope of this review. Finally, the institution of an EU registry of HE applications and outcomes represents a priority to improve transparency, reduce patient risks, increase efficiency of health systems, facilitate company awareness of business opportunities and boost progressive entry of ATMPs into the therapeutic repertoire of health systems.

Anti-CD19 CAR T cells in combination with ibrutinib for the treatment of chronic lymphocytic leukemia.

In chronic lymphocytic leukemia (CLL) patients who achieve a complete remission (CR) to anti-CD19 chimeric antigen receptor T cells (CART-19), remissions are remarkably durable. Preclinical data suggesting synergy between CART-19 and the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib prompted us to conduct a prospective single-center phase 2 trial in which we added autologous anti-CD19 humanized binding domain T cells (huCART-19) to ibrutinib in patients with CLL not in CR despite ≥6 months of ibrutinib. The primary endpoints were safety, feasibility, and achievement of a CR within 3 months. Of 20 enrolled patients, 19 received huCART-19. The median follow-up for all infused patients was 41 months (range, 0.25-58 months). Eighteen patients developed cytokine release syndrome (CRS; grade 1-2 in 15 of 18 subjects), and 5 developed neurotoxicity (grade 1-2 in 4 patients, grade 4 in 1 patient). While the 3-month CR rate among International Working Group on CLL (iwCLL)-evaluable patients was 44% (90% confidence interval [CI], 23-67%), at 12 months, 72% of patients tested had no measurable residual disease (MRD). The estimated overall and progression-free survival at 48 months were 84% and 70%, respectively. Of 15 patients with undetectable MRD at 3 or 6 months, 13 remain in ongoing CR at the last follow-up. In patients with CLL not achieving a CR despite ≥6 months of ibrutinib, adding huCART-19 mediated a high rate of deep and durable remissions. ClinicalTrials.gov number, NCT02640209.

Decade-long leukaemia remissions with persistence of CD4+ CAR T cells.

The adoptive transfer of T lymphocytes reprogrammed to target tumour cells has demonstrated potential for treatment of various cancers1-7. However, little is known about the long-term potential and clonal stability of the infused cells. Here we studied long-lasting CD19-redirected chimeric antigen receptor (CAR) T cells in two patients with chronic lymphocytic leukaemia1-4 who achieved a complete remission in 2010. CAR T cells remained detectable more than ten years after infusion, with sustained remission in both patients. Notably, a highly activated CD4+ population emerged in both patients, dominating the CAR T cell population at the later time points. This transition was reflected in the stabilization of the clonal make-up of CAR T cells with a repertoire dominated by a small number of clones. Single-cell profiling demonstrated that these long-persisting CD4+ CAR T cells exhibited cytotoxic characteristics along with ongoing functional activation and proliferation. In addition, longitudinal profiling revealed a population of gamma delta CAR T cells that prominently expanded in one patient concomitant with CD8+ CAR T cells during the initial response phase. Our identification and characterization of these unexpected CAR T cell populations provide novel insight into the CAR T cell characteristics associated with anti-cancer response and long-term remission in leukaemia.