Meeting the Promise of Allogeneic Cell Therapies
Stefan Braam, Chief Technology Officer, Cellistic
Allogeneic cell therapies are poised to redefine immunotherapy by overcoming the limitations of donor-based models. In this article, Stefan Braam, Chief Technology Officer at Cellistic, explores how induced pluripotent stem cell (iPSC) derived NK cell therapies are providing a scalable, off-the-shelf alternative to donor-derived models, reducing manufacturing variability and accelerating clinical access. Leveraging unique insight, Braam explores the role of automation, gene editing, and process innovation in enabling future growth in this expanding therapeutic area.
A turning point for cell therapy
The global cell and gene therapy (C>) market is undergoing a significant transformation. Driven by the urgent need for scalability, consistency and affordability, the field is moving away from highly personalised, patient-specific approaches toward standardised, industrialised models. This evolution echoes the earlier shift seen in monoclonal antibody production, where bespoke processes gave way to scalable platforms capable of serving global patient populations. Now valued at more than $20 billion and projected to grow further by 2030, the C> landscape is increasingly focused on allogeneic solutions that promise wider accessibility and reduced manufacturing complexity.
Autologous therapies, while groundbreaking in their personalised approach, are increasingly recognised as commercially unsustainable on a large scale. Each patient’s therapy requires individualised manufacturing, beginning with cell collection from the patient, followed by a multi-week production cycle that includes genetic modification, expansion, and rigorous quality testing before the therapy is returned to the clinic. This process often exceeds four to six weeks, during which patients with aggressive diseases may experience disease progression. Furthermore, manufacturing at this scale is hindered by labor constraints and logistical challenges, including cold-chain management, as well as challenges arising from variable patient health statuses, which can significantly impact cell yield and quality. These factors contribute to the exceptionally high costs of autologous therapies, often reaching hundreds of thousands of dollars per patient, alongside limited accessibility.
In contrast, allogeneic therapies offer the potential for an “off-the-shelf” solution produced from master cell banks, breaking the dependency on patient-specific manufacturing and enabling treatments to be made at an industrial scale. This shift is a response to the urgent need for accessible, scalable and economically viable cell therapies worldwide.
The rise of iPSC-NK therapies
Allogeneic iPSC-derived cell therapy platforms are specifically designed to enable highly complex gene edits and accurately select cells carrying the intended modifications, minimising off-target effects. Key design criteria for a platform include:
• Precise multiplex gene editing: The ability to introduce multiple, targeted genetic modifications without off-target effects.
• Efficient selection of edited cells: Rapid and accurate identification of cells that carry the intended modifications.
• Sterility and traceability: Maintaining a contamination-free environment and ensuring full digital traceability throughout the development process.
• Monoclonality assurance: Confirming that therapeutic clones originate from a single, genetically stable cell to meet regulatory expectations.
Within this shift, NK cells derived from iPSCs have emerged as a promising modality. These cells combine innate cytotoxicity with the benefits of a renewable, genetically stable cell source. Emerging clinical data continue to validate their potential, with iPSC-derived CAR-NK therapies, such as FT596, showing encouraging results in hematologic cancers, demonstrating favorable response rates and lower toxicity compared to autologous CAR-T treatments. As the industry seeks more scalable solutions, iPSC-NK therapies are increasingly viewed as an essential component of the future immunotherapy landscape [2,3].
However, moving iPSC-NK therapies from laboratory research into clinical and commercial practice presents a distinct set of challenges. Developers must navigate science, technology, and regulatory complexities to ensure these therapies can be reliably and effectively delivered to patients at scale.
Navigating the challenges of scale and complexity
From lab bench to GMP
The leap from early-stage research to clinical-grade manufacturing of iPSC-NK therapies introduces significant hurdles. Processes that are robust at a laboratory scale often do not seamlessly translate to the larger volumes, regulatory standards, and operational complexity required in GMP manufacturing. One of the primary challenges is maintaining consistency in cell quality and function as production scales. Variability in culture conditions, even subtle fluctuations in oxygen levels, shear stress, or nutrient gradients, can significantly impact cell viability and therapeutic potency.
Traditional two-dimensional culture systems, a staple of laboratory research, are particularly problematic for scaling. These systems require large amounts of physical space, intensive manual labor, and frequent interventions, all of which increase the risk of contamination, batch failure, and process variability. For example, scaling from ten 2D plates to hundreds or thousands introduces physical and operational bottlenecks that are unsustainable in a clinical or commercial environment.
Adopting suspension-based, closed bioreactor systems is now viewed as essential for scale-up. These systems provide a controlled environment that supports larger batch sizes with significantly reduced manual input. Bioreactors allow precise control over parameters like dissolved oxygen, agitation rates, and pH, ensuring more reproducible results. However, the transition from adherent to suspension culture requires re-optimising differentiation protocols, validating shear tolerance thresholds for cells, and ensuring the media composition remains supportive of both cell expansion and differentiation at scale.
In addition to mastering suspension-based bioreactor operations, developers must also consider how to introduce flexibility into the manufacturing process. One effective strategy is process modularity. Introducing cryopreservation steps at defined points in the workflow, such as after creating a master cell bank or lineage-specific intermediates, adds crucial flexibility. This modular approach enables developers to separate early-stage production from final cell expansion, improving scheduling and inventory management while reducing waste.
Driving toward economic feasibility
Innovation, while crucial for scalability and product quality, comes at a considerable cost. Manufacturing remains resource-intensive, with complex workflows involving multiple stages of cell isolation, gene editing, expansion, differentiation and formulation. Each stage requires specialised materials and highly trained personnel, driving up costs. Manual handling introduces not only variability but also higher labor expenses, increased facility downtime and greater risk of contamination.
Drug developers and manufacturers of iPSC-NK therapies must carefully consider how different technologies and approaches could impact economic feasibility and provide potential benefits:
• Single-use systems
The field is increasingly adopting closed, single-use bioreactor systems, driven by their consistency as well as their cost benefits. These systems minimise contamination risks, reduce labor input, and streamline cleaning requirements. By eliminating the need for stainless steel infrastructure, they lower facility construction costs and shorten turnaround times between production runs.
• Modular manufacturing
The shift toward modular manufacturing, where discrete units handle specific steps like expansion, harvest or formulation, enhances flexibility. Facilities designed for parallel, rather than sequential, workflows can process multiple batches simultaneously. This greatly improves throughput and provides redundancy, reducing the impact of potential batch failures.
• Real-time monitoring
Real-time monitoring tools are becoming indispensable. Sensors capable of screening pH, dissolved oxygen, glucose, and lactate concentrations enable early detection of deviations that could compromise cell quality. Integrated data platforms collect and process parameters from multiple batches, feeding into predictive models that help optimise process conditions over time.
• Economic modeling
Economic modeling has become a critical tool in process development, helping manufacturers navigate the financial realities that accompany these advanced, resource-intensive workflows. Companies use sensitivity analyses to identify the most significant cost drivers, whether they stem from raw material usage, labor or equipment downtime. These insights inform decisions about where to invest in automation or process optimisation, ensuring that capital investments deliver the highest return while supporting reliable, scalable production.
Building in quality from the start
Ensuring regulatory compliance becomes increasingly complex as cell therapies, such as iPSC-NK therapies, scale from laboratory production to widespread clinical use. Unlike small-molecule drugs, cell therapies are living products. As a result, quality depends heavily on the integrity of the manufacturing process itself. This makes rigorous quality management essential from the earliest stages of development.
Regulatory agencies, including the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA), require detailed documentation demonstrating that manufacturing processes consistently produce a product that meets predefined quality standards. These standards include identity (confirming the presence of key surface markers such as CD56, CD16 and NKG2D) as well as viability, purity, and safety.
Potency assays present a particularly challenging area, as they must reliably demonstrate the functional ability of NK cells to target and destroy tumor cells. These assays often use standardised target cell lines and are validated to ensure consistent performance across batches. Similarly, tests to confirm the absence of undifferentiated iPSCs are critical for safety, as any residual pluripotent cells could pose a tumorigenic risk.
Beyond product-specific testing, regulators also focus on the manufacturing environment. Emerging regulatory frameworks are beginning to accommodate real-time release testing (RTRT) for advanced therapies [6]. By integrating in-line sensors and predictive analytics, manufacturers can potentially release batches based on process data rather than waiting for extensive post-production testing. This shift not only accelerates delivery but also aligns with regulators' increasing comfort with data-driven quality assurance in the C> space. Requirements for environmental monitoring, raw material traceability, equipment validation and change control processes remain critical. As production scales, electronic batch records and centralised quality management systems become essential for maintaining compliance. These digital systems provide real-time oversight, reduce the risk of human error and facilitate audits by delivering transparent, traceable data across multiple manufacturing sites.
Gene editing at scale: Complexity meets precision
Gene editing is foundational to allogeneic iPSC-based therapies, enabling enhancements such as improved tumor targeting, immune evasion and extended persistence. Unlike other cell types, iPSCs present unique challenges for gene editing. Their lower transfection efficiency and sensitivity to culture conditions make multiplex editing particularly complex.
Introducing multiple gene edits simultaneously, often a combination of knock-ins for enhanced functionality and knockouts for immune cloaking or checkpoint inhibition, requires extremely precise tools. CRISPR-based systems are the most commonly used, but even high-fidelity nucleases can introduce off-target effects if not carefully managed.
The challenge extends beyond executing the gene edits; it also involves the complex task of identifying and isolating the correctly edited clones from a large pool of candidates. After editing, hundreds or thousands of candidate colonies are screened using PCR, next-generation sequencing and functional assays to verify both on-target success and absence of unwanted changes. This is a labor- and data-intensive process.
Clonal stability is critical. A clone selected for manufacturing must not only contain the desired edits but also retain genomic integrity over multiple passages. Any chromosomal abnormalities, translocations or unexpected mutations could compromise safety or efficacy, and as a result, extensive genomic screening is essential.
Automation can help overcome these challenges. Robotic systems now handle tasks such as single-cell seeding, media exchanges and clone picking. These systems not only reduce contamination risks but also improve the reproducibility of complex gene editing workflows. Furthermore, automated imaging tools allow real-time monitoring of clone growth and morphology, flagging any anomalies early in the development process.
How automation supports modern cell line development
Manual methods are no longer sufficient to meet the demands of clinical-scale gene-edited iPSC manufacturing. The complexity of these workflows, especially when dealing with multiple gene edits, clonal selection and stability assessment, makes automation not just beneficial but essential. Automation can be leveraged throughout iPSC cell line development in different ways:
Clonal assurance
Automated platforms enable clonal assurance by precisely executing single-cell deposition, often with imaging-based double confirmation of monoclonality. This ensures that each clone can be tracked from initial isolation through expansion and final selection, which is a critical requirement for regulatory submissions.
Sterility control
Enclosed robotic systems operating under Grade A air supplies eliminate the need for manual interventions during sensitive steps such as media changes, transfection and clone expansion. This can significantly reduce contamination risks while improving batch reliability.
Digital traceability
Full digital traceability can be built into modern automation platforms, allowing seamless audit trails and data capture. Every action, from liquid handling to imaging and colony screening, is recorded and associated with each clone. This data integrity becomes vital for regulatory filings and ongoing quality management.
Parallel processing and artificial intelligence (AI) integration
Parallel processing capabilities mean that hundreds of clones can be developed, monitored and characterised simultaneously, dramatically compressing development timelines. The rich datasets generated from these automated systems can be fed into machine learning algorithms that refine clone selection, predict growth characteristics and identify potential process improvements, ultimately driving greater efficiency and precision in manufacturing.
The future requires continued adaptability
As the iPSC allogeneic cell therapy field advances, regulatory landscapes are evolving alongside technological innovations like AI-driven process optimisation and decentralised manufacturing models. Developers must continue investing in infrastructure, sustainability and data-driven strategies to ensure long-term success.
The lessons learned in scaling iPSC-NK platforms will set the foundation for a broader range of cell therapies in the years ahead. As demand for off-the-shelf, standardised treatments continues to grow, the industry must prioritise continued innovation in bioprocessing, quality control, and regulatory alignment. At the same time, developers must be prepared to adopt new technologies, such as AI-driven process optimisation and decentralised manufacturing models. These forward-looking strategies will be crucial in ensuring that cell therapies not only achieve clinical success but are delivered reliably, efficiently, and at scale to meet the global needs of patients.
References:
1. Grand View Research. Cell Therapy Market Size, Share & Trends Analysis Report, 2023–2030. https://www.grandviewresearch.com/horizon/outlook/cell-therapy-market-size/global
2. BSH. Natural Killer Cell Immunotherapy Shows Promise. https://b-s-h.org.uk/about-us/news/natural-killer-cell-immunotherapy-shows-promise
3. PubMed. https://pubmed.ncbi.nlm.nih.gov/40029829/
4. Frontiers in Immunology. https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.841107/full
5. Nature. https://www.nature.com/articles/s41392-024-01809-0
6. GMP Compliance. FDA Expectations Concerning Real-Time Release Testing (RTRT). https://www.gmp-compliance.org/gmp-news/fda-expectations-concerning-real-time-release-testing-rtrt
Author Bio
Stefan Braam is the co-founder and Chief Technical Officer of Cellistic, with over a decade of experience in stem cell technology, product development, and general management. He won the NGI Venture Challenge (2009) and the Niaba Biobusiness Masterclass (2010), has published in several leading scientific journals, is an inventor on multiple patent families, and has secured numerous grants and commercial research collaborations.
