From Discovery to Delivery: Solving the iPSC Cell Therapy Manufacturing Bottleneck
Key Insights
iPSC-derived cell therapies have entered clinical trials for conditions including macular degeneration (search), Parkinson's disease (search), and oncology, validating the therapeutic potential of these approaches.
Manufacturing remains a critical bottleneck, with iPSC processes running 60–90 days in bioreactors, creating significant cost of goods and variability risks that demand robust process development.
Experts emphasize that "the cells are the product," requiring quality-focused, GMP-compliant, closed, and automated manufacturing systems to ensure safety, purity, identity, and potency.
The field of induced pluripotent stem cell (iPSC)-based cell therapy has crossed a critical threshold. Once confined to academic discovery, iPSC-derived therapies are now delivering clinical proof-of-concept across ophthalmology, neurology, and oncology. But as the pipeline matures, the central challenge is no longer purely biological—it is manufacturing. Developers, investors, and regulators are increasingly focused on whether these complex living products can be produced at scale with the reproducibility, quality, and cost structure required to reach patients.
Sarah Gilpin, Principal Scientist in Process Development Services at Sartorius (search), describes the trajectory in three phases: the early discovery era anchored by hematopoietic stem cell transplantation and embryonic stem cell biology; a translational period sparked by the 2007 discovery of iPSC reprogramming; and the current phase, which she characterizes as "bringing this to clinical reality." Today, iPSC-derived retinal cell transplantation has moved into clinical trials for macular degeneration (search), Parkinson's disease (search) therapies are under investigation, and oncology platforms are advancing natural killer (NK) cell and T-cell approaches. "We're really at this precipice of success where clinical trials are increasing globally," Gilpin says.
The cell is the product
A fundamental shift distinguishes cell therapy manufacturing from traditional biopharmaceutical production. "The cells are the product now. They're not a byproduct. We're not making vectors or proteins," Gilpin explains. This reality imposes unique demands: cells are living, highly plastic entities, and small changes in media, culture conditions, or handling can amplify into significant functional consequences. "If the cells don't do what we need at the end, there was no point in making them in the first place."
David Hermanson, director of cell therapy product management at Bio-Techne (search), echoes this concern from a historical perspective. "When I started, T cell differentiation from an iPSC wasn't really possible. Now several biotech companies are founded on iPSC-derived T cells." He notes that iPSC-derived cell therapies are "now where immune-cell therapy was 10 years ago," but cautions that the bar for investment has risen. "While a promising target or novel mechanism of action might have been enough to secure funding in years past, investors today are increasingly concerned about manufacturing and scale-up."
Quality by design: defining what good looks like
High-quality stem cells, Gilpin argues, must meet critical quality attributes established before process development begins. These fall into well-established categories: safety, purity, identity, and potency. "You need to make sure that you have the cell type that you want at the beginning—your pluripotent cells—verify they are truly pluripotent and function as such, and ensure you have the desired cell type at the end of differentiation, confirmed by phenotype and function."
Crucially, quality is not merely about cell quantity. "We're not just growing cells to have a whole bunch of cells—they have to do something," Gilpin says. Developers must define mechanism-of-action readouts: Do the cells need to engraft? Secrete therapeutic factors? Kill other cells in an oncology setting? The assays and criteria that answer these questions are the development team's responsibility and form the backbone of the regulatory strategy.
The scalability conundrum
Scaling iPSC-based therapies presents challenges that dwarf those of autologous cell therapies like CAR-T. While CAR-T processes may involve less than a week in culture, "iPSC processes in bioreactors can run 60 to 90 days," Gilpin notes. The cost of goods and the risks associated with extended timelines directly impact variability and quality. "You can't simply scale by making a bigger bioreactor. You have to think about all of these steps along the way—expansion, differentiation—and ensure that the phenotype and function is stable at the end of your process."
Julia Hatler, vice president of Bio-Techne (search)'s advanced cell systems unit, frames the challenge as "starting with the end in mind"—a phrase she hears frequently at cell therapy conferences. For today's developers, that means asking: "How do we develop a scalable process that still provides a durable and safe drug product?" One major goal is maximizing batch-to-batch consistency by creating workflows with fewer steps to reduce variability.
Bio-Techne (search)'s G-Rex bioreactors, supplied through its part-ownership of Wilson Wolf (search), offer modularity to ease bottlenecks. "A bioreactor that can be decoupled from the upstream and downstream parts of the workflow allows for the system to be used for multiple patients," Hatler explains.
Navigating the RUO-to-GMP transition
A critical inflection point in cell therapy development is the transition from research use only (RUO) reagents to good manufacturing practice (GMP)-grade materials. Hannah Maple, who leads Bio-Techne (search)'s Bristol site, emphasizes that "researchers have to match the quality grade of the reagents to the risk profile of the experiments being performed." When a developmental therapy enters clinical trials, managing this risk becomes paramount, yet knowing exactly when to switch can be difficult. "Collaborating with a GMP manufacturer early and establishing a clear path from an RUO reagent to a GMP equivalent can save downstream disruption that might delay clinical trials."
Bio-Techne (search) is investing to meet growing demand, with a new facility in Bristol focused on scaling up GMP manufacture for small molecules. "It will enable the expansion of the GMP small molecules portfolio to help the field reach its potential and support developers in the later phases of clinical trial who are looking ahead to commercialization," says Maple.
Cell line variability and regulatory groundwork
Gilpin stresses that "iPSC is not one thing." Cell lines created from different donors "have their own personalities," and a process developed for one line may not translate directly to another. The choice of cell line is consequential because it cannot easily be changed once development and regulatory approval are underway. "That choice of cell line and then developing the process around that specific cell line is a necessary part of the task."
Regulatory precedent for these novel modalities remains limited globally, requiring a collaborative approach. For first-in-human studies, "a lot of groundwork must be established to define appropriate frameworks, safety parameters, and quality standards that will guide future development in this field," Gilpin says. Beyond manufacturing, healthcare infrastructure must also evolve. "These aren't medicines you simply take out of the fridge or ship in a box or pill container." Cryopreservation, storage, transportation, and administration all require substantial groundwork because the paradigm is "fundamentally different from what we've done historically."
Partnership as a development philosophy
Both Sartorius (search) and Bio-Techne (search) emphasize genuine partnership over transactional vendor relationships. Gilpin describes Sartorius's philosophy as "fundamentally about partnership," leveraging subject matter expertise and regulatory and manufacturing capabilities to work collaboratively with academic groups, startups, and large pharma alike. The approach involves technical assessment, design of experiments, process optimization, scale-up, and seamless transfer to GMP clinical manufacturing—with the same teams on both sides to avoid the challenges of third-party handoffs.
Hermanson offers a forward-looking assessment: "The companies who succeed over the next 10 years will be the ones best able to control their manufacturing processes. Once the science is solved, the next step is always the practicality of manufacturing at scale to be able to deliver reliable, game-changing benefits to patients."