Surveying local CAR T-cell manufacturing processes to facilitate standardization and expand accessibility

Abstract

Background

Chimeric antigen receptor T-cell (CAR T-cell) therapies have shown significant promise in treating cancers and other diseases. However, the manufacturing processes for CAR T-cell therapies exhibit considerable variability, which can affect treatment consistency and patient outcomes. While centralized manufacturing models dominate, local decentralized approaches, including point-of-care production, are being explored to address logistical and access challenges. This study aims to evaluate the current landscape of local CAR T-cell manufacturing at academic institutions.

Methods

A comprehensive, cross-sectional survey was distributed to 130 FACT and/or JACIE accredited academic institutions globally. The survey, developed from semi-structured interviews with CAR T-cell manufacturing experts, assessed practices in cell modification methods, equipment protocols, and regulatory challenges. Data were analyzed using descriptive statistics, comparing responses across institutions and regions.

Results

45 of the 130 institutions (35 from the United States and 10 internationally, from the European Union, the United Kingdom, and Australia) responded to the survey (35% response rate). Of the 45 responding institutions, 40 were actively engaged or planning to engage in CAR T-cell production, while five had no plans to initiate manufacturing. Within the 40 institutions engaged in CAR T-cell production, 63% (25/40) reported active manufacturing, while 37% (15/40) were in the process of developing manufacturing capabilities. The most commonly reported barriers to local manufacturing were cost constraints (70%, 28/40), regulatory complexities (70%, 28/40), and facility requirements (57%, 17/40). Variability in product quality was cited by 73% (29/40) of institutions. Equipment costs and the need for specialized training emerged as major challenges, particularly for international institutions. Institutions also highlighted the need for automated platforms, with 60% (24/40) using the Miltenyi CliniMACS Prodigy and 50% (20/40) using the Lonza Cocoon.

Conclusions

This study highlights the widespread adoption of local CAR T-cell manufacturing and the significant variability in production processes across institutions. The findings emphasize the importance of establishing quality control benchmarks and data reporting frameworks to improve product consistency and access to CAR T-cell therapies. Addressing barriers such as cost, infrastructure, and regulatory challenges through standardization efforts and international collaboration could enhance the reproducibility, scalability, and accessibility of CAR T-cell therapies globally.

Introduction

Chimeric antigen receptor T-cell (CAR T-cell) therapies have emerged as groundbreaking treatments for cancers and potentially autoimmune diseases [1, 2]. By re-engineering a patient’s immune cells to target and destroy cancer, CAR T-cell therapies have demonstrated remarkable efficacy. The current centralized CAR T-cell manufacturing model involves complex, multi-step processes including cell harvesting, genetic modification, expansion, cryopreservation, and reinfusion. These steps require advanced infrastructure, specialized equipment, and highly trained personnel. Centralized production benefits from economies of scale and appropriate quality and regulatory oversight, ensuring product consistency and safety. However, it has notable challenges: high costs, extended production timelines, limited capacity, and scheduling logistics related to transporting cells to and from centralized facilities [3,4,5]. These inefficiencies result in prolonged vein-to-vein times—the period from cell collection to reinfusion—which can significantly impact critically ill patients who require timely treatment [6, 7]. As demand for CAR T-cell therapies continues to grow, the strain on centralized systems will be exacerbated, emphasizing the need for innovative alternatives [8,9,10,11,12].

Local, also known as point of care or decentralized, CAR T-cell manufacturing offers a promising alternative to the centralized model (Fig. 1) [10,11,12,13,14,15]. This approach leverages institutional or regional current Good Manufacturing Practice (GMP) fixed or mobile laboratories to provide local production of CAR T-cell cells to expand the availability of manufacturing [16]. Also, by bringing the manufacturing process closer to the patient, local CAR-T manufacturing can reduce the time and costs associated with transportation and central processing, improving treatment timelines and mitigating healthcare inequalities for underserved populations [17]. This method has the potential to expand the reach of CAR T-cell therapies while also addressing challenges related to supply chain disruptions, regulatory compliance, and the scalability of treatment options because decentralized manufacturing would enable more flexibility in manufacturing methods if product safety, quality, identity, potency, and purity (SQUIPP) is maintained [18].

Fig. 1

Comparison of CAR-T manufacturing models

Despite these advancements, the variability in CAR T-cell manufacturing processes remains a significant obstacle to broader adoption and success. Inconsistent practices across institutions, from cell sourcing and genetic modification to culture conditions and quality control, contribute to disparities in therapeutic outcomes [3, 4, 19,20,21]. The need for scalable and consistent treatment becomes even more pressing as CAR T-cell therapy expands beyond hematologic diseases into solid tumors and autoimmune diseases. As CAR T-cell applications broaden, variations in clinical practice will likely increase, worsening disparities to this lifesaving treatment [22]. To address this, establishing standardized manufacturing and treatment protocols are essential to ensure consistency in product SQUIPP. By aligning regulatory requirements and sharing knowledge, institutions across the world can build a more consistent and scalable model for CAR T-cell manufacturing.

This study seeks to address the challenges of variability in CAR T-cell manufacturing by surveying key stakeholders across academic institutions engaged in CAR T-cell production. By analyzing differences in cell processing techniques, genetic modification methods, culture protocols, and quality control practices, the research aims to identify the key obstacles to local manufacturing and explore pathways to overcome them, providing critical insights to decrease variability and equitable access to CAR T-cell therapies globally. The study integrates insights from institutions in the US and internationally, offering a comprehensive perspective on current practices and challenges.

Materials and methods

To comprehensively analyze the variability and challenges in local CAR T-cell manufacturing processes, we employed a mixed-methods approach that integrated a web-based survey with semi-structured interviews. This multi-faceted methodology aimed to capture both quantitative data and qualitative insights, providing a robust foundation for understanding the landscape of CAR T-cell manufacturing and identifying opportunities for standardization.

Semi-structured interviews

To develop the survey, we conducted semi-structured interviews with academic US experts actively engaged in CAR T-cell manufacturing to better comprehend real-world issues. The interviews were designed to understand the nuances of local manufacturing processes, exploring challenges, innovative solutions, and future perspectives. The experts provided critical insights into the challenges of standardization, emphasizing the institution-specific nature of most protocols and the need separate the cell therapy process into modular components for improved consistency. Differences in automation reliance in the manufacturing process was identified as a potential factor in variability, though both experts noted differences in protocols across equipment and institutions that limit scalability.

The interviews also highlighted tensions between academic and industry partnerships, with the former prioritizing cost-effectiveness and innovation, and the latter prioritizing scalability and commercialization. Regulatory compliance was a shared concern, with one expert advocating for streamlined FDA processes and the other emphasizing the importance of appropriate quality control and regulatory oversite in GMP facilities. Barriers to patient access, such as high costs, limited availability, and insurance challenges, were also discussed.

Key themes from these interviews informed the survey design, ensuring it addressed critical issues such as manufacturing variability, regulatory hurdles, automation, and accessibility. The qualitative data from the experts were analyzed using thematic coding to refine survey questions and contextualize findings, enhancing the study's methodological rigor.

Web-based survey

A comprehensive cross-sectional survey was developed to assess CAR T-cell manufacturing practices across academic institutions GMP facilities. Survey items covered the following key domains:

• Cell sourcing and processing techniques: Cell sourcing, pre-processing steps, and activation methods.

• Genetic modification methods: Technologies employed for T-cell engineering, efficiency of transduction or transfection, and selection criteria.

• Culture conditions and expansion protocols: Media compositions, incubation parameters, and approaches for scaling product production.

• Product characteristics and quality control measures: End-product specifications, release criteria, and quality control and assurance processes.

• Automation and manufacturing platforms: The use of automated or semi-automated systems in manufacturing workflows.

• Regulatory compliance challenges: Difficulties in meeting local, national, and international regulatory standards.

The survey was distributed via REDCap, a secure electronic data capture system hosted by the Duke University School of Medicine. Data collection spanned a six-month period from June 2024 to November 2024. Institutions were invited to participate through email communications and professional networks, and responses were anonymized to ensure confidentiality. Descriptive statistics were calculated to summarize the survey data, and qualitative responses were coded and thematically analyzed.

Results

The RedCap survey was sent to 130 FACT (Foundation for the Accreditation of Cellular Therapy) and/or JACIE (Joint Accreditation Committee of the International Society for Cellular Therapy and European Group for Blood and Marrow Transplantation) accredited academic institutions involved in more than minimal manipulation in cellular processing across 12 countries. 45 institutions, 35 in the US and 10 international (European Union [EU], the United Kingdom [UK], and Australia), responded (response rate of 35%) (Table 1). 40 institutions were either actively involved in CAR T-cell manufacturing or planning to initiate production, while the other 5 not involved in manufacturing with no future plans for production.

Table 1 Quantitative survey results

Overview of centers involved in manufacturing

Among the 40 institutions currently involved in or planning to start CAR T-cell production, 63% (25/40) reported actively manufacturing CAR T-cell therapies, while the remaining 37% (15/40) were in the process of developing local manufacturing capabilities with plans to begin production within the next two years. US-based institutions were more likely to have active manufacturing (67%, 20/30) compared to their international counterparts (40%, 4/10), potentially reflecting earlier adoption and greater resource availability in the US. These US institutions also generally reported greater access to funding and infrastructure, with 67% (20/30) citing robust financial support for CAR T-cell manufacturing and 87% (26/30) indicating access to advanced manufacturing facilities. In contrast, international institutions, including those in the EU, UK, and Australia, frequently highlighted unique challenges. 70% (7/10) of these institutions reported difficulties in navigating multiple regulatory frameworks, which vary significantly across regions, and 70% (7/10) identified challenges in recruiting and retaining specialized personnel with expertise in CAR T-cell production.

Overview of centers not involved in manufacturing

The five institutions not engaged in CAR T-cell production nor planning to initiate production cited several barriers. The most commonly reported challenges were cost constraints (80%, 4/5) and a lack of specialized infrastructure (60%, 3/5). These institutions often relied on alternative strategies to meet patient needs. Of the institutions not planning to manufacture CAR T-cells in the future, four out of five institutions (80%) will continue to refer patients to other facilities, three (60%) will utilize commercially available CAR T-cell products, and two (40%) will participate in clinical trials managed by external organizations. These strategies highlight the reliance on external manufactured products when local manufacturing is not feasible.

Several key factors were identified as potential motivators for initiating CAR T-cell production. Access to appropriate manufacturing facilities was cited by 80% (32/40) of respondents, while 70% (28/40) emphasized the need for turnkey manufacturing solutions, and 60% (24/40) cited increased patient demand. International institutions placed a stronger emphasis on turnkey solutions, which could provide ready-to-use systems tailored to their specific needs, whereas US institutions were more focused on scaling their existing infrastructure to meet growing demand.

Protocols of manufacturing processes

The survey also showed significant variability in CAR T-cell manufacturing processes (Table 2). Of the 25 institutions that currently manufacture CAR T-cells, 21 reported on their institution’s protocols. 81% (17/21) employ anti-CD3/CD28 beads for T cell activation, 33% (7/21) use soluble antibodies and 43% (9/21) use artificial antigen-presenting cells. Additionally, 62% (13/21) of the institutions utilize T cell subset enrichment strategies. For genetic modification, 76% (16/21) of the institutions use lentiviral vectors, 33% (7/21) use retroviral vectors, and 24% (5/21) use mRNA. Furthermore, 48% (10/21) of the institutions perform additional genetic modifications beyond CAR transduction, with a typical transduction efficiency of 80%. In terms of culturing, the typical culture duration is 10 days, with an average fold-expansion of 50-fold and a total number of CAR T-cells produced per manufacturing run being approximately 1 billion cells. The percentage of T cells expressing CAR is reported to be 70% across surveyed institutions. CAR expression intensity is measured by 62% of institutions (13/21) using mean fluorescence intensity (MFI), while 38% of institutions (8/21) quantify CAR expression using molecules of equivalent soluble fluorochrome (MESF). Additionally, 67% (14/21) of the institutions monitor T cell phenotype and exhaustion markers. Regarding cryopreservation, 52% (11/21) of the institutions use passive freezing methods, while 48% (10/21) use controlled-rate freezing methods. The average vein-to-vein time across institutions is 22 days (range 20–30 days). The typical persistence of CAR T-cells in patients is observed to be between 1 and 3 months.

Table 2 Survey results on CAR-T manufacturing protocols

Among the 40 institutions involved in CAR T-cell production, 90% (36/40) reported utilizing some form of automation (Table 1). The most commonly adopted platforms included the Miltenyi CliniMACS Prodigy (60%, 24/40), Lonza Cocoon (50%, 20/40), and Gibco CTS Rotea (26%, 13/40). Some institutions utilized multiple platforms. US institutions demonstrated higher adoption rates for these automated systems, while international facilities often reported variability in their protocols, with many relying on semi-automated or manual processes.

Patient access emerged as a persistent issue across all surveyed institutions, driven by high costs, limited therapy availability, and infrastructure needs. US institutions reported greater disparities in access due to insurance-related barriers, while international facilities highlighted logistical challenges, particularly in remote regions. Both groups emphasized the need for broader healthcare coverage and increased support for underserved populations to expand access to CAR T-cell therapies.

Challenges to manufacturing

Institutions engaged in CAR T-cell production highlighted recurring challenges in implementing manufacturing processes (Table 3). Equipment costs were the most commonly reported barrier, cited by 70% (28/40) of responding institutions, followed by facility requirements (60%, 24/40) and the need for specialized personnel training (50%, 20/40). 70% (28/40) of the institutions reported regulatory compliance posed significant challenges with 60% (24/40) of institutions reporting difficulties in quality control and 50% (20/40) struggling with process optimization. US institutions were more likely to emphasize challenges related to navigating the FDA’s regulatory requirements, including the need to meet quality control standards and approval processes. In contrast, international institutions faced complexities arising from the need to comply with multiple regulatory bodies, such as the European Medicines Agency (EMA) in the EU, the Therapeutic Goods Administration (TGA) in Australia, and country-specific regulations in the UK. All respondents stressed the importance of clearer guidelines and collaborative efforts to streamline compliance and maintain consistent manufacturing standards.

Table 3 Qualitative survey results

Discussion

This survey highlights significant variability in local CAR T-cell manufacturing processes, both within US institutions and internationally. The results underscore the complexity of CAR T-cell production, with variations in cell sourcing, genetic modification methods, culture conditions, and quality control practices across institutions. This variability raises concerns regarding the consistency and replicability of product quality, potentially affecting safety, efficacy, and clinical outcomes across patients. These findings are consistent with other studies showing that the lack of standardized protocols is a major barrier to the widespread manufacturing of CAR T-cell therapies [21].

Unlike centrally manufactured commercial CAR T-cell products, which are developed by different companies and produced under highly standardized protocols, there is currently no FDA-approved local manufacturing model for CAR T-cells. However, the FDA has acknowledged the growing interest in decentralized manufacturing and is actively exploring regulatory frameworks to support its implementation [23]. As academic centers seek to expand local CAR T-cell production, broader standardization efforts—such as utilizing approved platform technologies, best practices for quality control testing, data reporting, and manufacturing workflows—could help harmonize processes across institutions, improving reproducibility and facilitating broader access to CAR T-cell therapy.

Local manufacturing could alleviate access barriers to accessibility by increasing the number of manufacturing slots available and by reducing production costs [17]. For instance, point-of-care facilities can enable rapid, on-site production for patients, while regional hubs could optimize supply chains over larger geographic areas. However, cost and infrastructure limitations remain the most prominent barriers to local CAR T-cell manufacturing. US and international institutions identified high manufacturing costs, lack of specialized facilities, and the need for trained personnel as significant obstacles to establishing local manufacturing capabilities. Regulatory complexities further complicate the process, with US institutions primarily navigating FDA requirements and international institutions contending with varying regulatory frameworks across different countries [24]. This variability hinders the development of universal standards for CAR T-cell production.

Another challenge identified was ensuring consistency in product SQUIPP. Although automated platforms like the Miltenyi CliniMACS Prodigy and Lonza Cocoon are increasingly used to streamline CAR T-cell production, variability in protocols and product characteristics persists¹⁹. These inconsistencies can lead to differences in the efficacy of engineered T-cells and affect therapeutic outcomes. Standardized guidelines could address key variables, such as cell source selection, genetic modification techniques, culture conditions, and quality control assays, providing a uniform framework for production. This would help ensure more consistent product quality across institutions, improving the reliability and efficacy of CAR T-cell therapies and enabling better therapeutic outcomes.

To address these challenges, standardizing CAR T-cell manufacturing protocols is crucial. Establishing uniform guidelines for cell sourcing, genetic modification, culture conditions, and quality control measures would help mitigate variability and ensure that CAR T-cell products meet consistent safety and efficacy standards across institutions. It is important to clarify that standardization does not imply rigid uniformity across all aspects of CAR T-cell manufacturing. Rather, standardization efforts should focus on establishing core quality control benchmarks and data reporting frameworks that allow for comparability across institutions while preserving flexibility for process optimization and development of innovative CAR T-cell therapies. The vision for scalable local manufacturing involves maintaining consistent manufacturing workflows while allowing the viral vector or gene modification platform to be tailored to different disease indications. As seen in other therapeutic areas, such as gene therapy and stem cell research, regulations that standardize critical process parameters, quality attributes, analytical methods, product characterization, manufacturing process controls, and risk-based validation approaches to yield clinically equivalent products have been instrumental in ensuring consistent outcomes and regulatory compliance [25]. By defining core product characterization methods—such as flow cytometry-based CAR expression analysis or viability measurements—institutions can improve reproducibility while enabling process flexibility. For CAR T-cells, such standardization would not only improve quality control but also facilitate the scaling of manufacturing processes, making therapies more accessible and cost-effective, especially in underserved regions.

An interesting aspect of CAR T-cell manufacturing is the training and development of GMP personnel, which often represents a critical gap for institutions seeking to establish local production. In the US, organizations such as the California Institute for Regenerative Medicine (CIRM) and programs at institutions like North Carolina State University have emerged as leaders in training personnel for Good Manufacturing Practice (GMP) compliance [26, 27]. These initiatives address a key barrier by creating a skilled workforce equipped to handle the complexities of CAR T-cell production. Additionally, there is a notable push-and-pull dynamic between academia and industry, as individuals frequently move between these sectors. Many academic GMP teams consist of professionals who previously worked in industry or received specialized training at programs like those offered by NC State. Addressing this dynamic will be essential to sustaining a skilled workforce capable of advancing CAR T-cell manufacturing across academic and industry settings [28].

Moreover, standardization frameworks can help protect institutions from becoming locked into proprietary platforms or technologies that may become obsolete or commercially unavailable. As noted by the results, many academic GMP teams rely on platform technologies for cell expansion or quality control testing, which raises concerns about continuity if vendors discontinue products. By defining common testing parameters and data reporting guidelines, institutions can future-proof their manufacturing programs and foster a more collaborative environment for academic CAR T-cell manufacturing. Ultimately, the goal is not to impose rigid manufacturing protocols but to create a shared foundation that enables scalable, reproducible CAR T-cell therapies while maintaining the flexibility needed to adapt to evolving technologies and clinical needs.

While this survey offers valuable insights, there are some limitations. The 40-institution sample may not fully capture the global diversity of CAR T-cell manufacturing practices, and focusing on academic institutions limits generalizability, excluding commercial and other non-accredited facilities. Additionally, self-reported data may introduce bias, and international responses may be influenced by regional regulatory and economic factors. Centers involved with processing hematopoietic stem cells and blood may have a standardization bias given their experiences [29]. The survey also focused on manufacturing processes, not addressing patient outcomes and cost-effectiveness. Future studies should address these areas for a more comprehensive view of CAR T-cell therapy. Furthermore, this study does not explore the risks associated with local manufacturing, particularly the financial burden to the local institution because of the need for specialized equipment, staff training, and adherence to stringent quality control measures. Another challenge is how the institution is reimbursed for these costs if they are not approved products as the FDA Cost Recovery model does not cover all costs [30, 31]. Local manufacturing should decrease patient and insurance cost, as locally manufactured products are estimated to be $80k compared to $350–500k for commercially available products, increasing patient access [17, 32]. Evaluating these financial and operational risks is crucial for the long-term feasibility of local CAR T-cell manufacturing, including funding sustainability, cost overruns, and supply chain management.

Future efforts should focus on sharing best practices and fostering international collaboration. The increasing adoption of automated CAR T-cell platforms offers an opportunity to standardize manufacturing, but this requires cross-institutional collaboration to align protocols and optimize platform performance. Customized solutions tailored to regional needs will also be crucial for overcoming infrastructure and resource limitations [21]. International cooperation will be essential to harmonize regulatory standards and create a global framework for CAR T-cell production.

Conclusions

In conclusion, the findings of this study underscore the need for standardized CAR T-cell manufacturing protocols, infrastructure, and training to mitigate variability and improve product consistency. The challenges identified—cost, infrastructure limitations, regulatory oversight, and product quality—are consistent with existing literature and highlight the need for concerted efforts to address these issues. Improving quality control could involve developing more efficient and affordable testing platforms. Additionally, standardized protocols, platforms, and reagents for manufacturing and quality control processes could further streamline operations and reduce variability. Addressing these needs, alongside fostering international collaboration, is essential to improving the accessibility and effectiveness of CAR T-cell therapies. Future research should focus on developing customized solutions for local manufacturing, aligning regulatory frameworks, and expanding the scope of studies to explore disparities in patient access, as well as the long-term clinical and economic outcomes of CAR T-cell therapy.