Pioneering Quality Control in Biomanufacturing of Cell and Gene Therapies

This content was first published by Cell and Gene Therapy Insights.

Lauren Coyle, Commissioning Editor, Cell & Gene Therapy Insights, speaks with Dhruv Sareen, Executive Director at Cedars-Sinai Biomanufacturing Center, and Jonathan Rodriguez, Quality Control Manager at Cedars-Sinai Biomanufacturing Center, about the roles of in-process controls, method validation, risk management, and automation in biomanufacturing.

They will highlight strategies to ensure product safety, consistency, and regulatory compliance for cell and gene therapy products.

Can you briefly tell us about your careers and what you are currently working on?

JR: I currently serve as Quality Control Manager at Cedars-Sinai Biomanufacturing Center (CBC). My background is primarily in academia, starting a few years ago in France at the University of Lyon, where I completed my Bachelor’s and Master’s degrees in Cell Biology, Genetics, and Pathology. I later completed a PhD in Therapeutic Engineering. Largely, my expertise lies in human stem cells, molecular biology, and process development in preclinical studies within a CGMP environment—all of which are aimed at accelerating stem cell therapy.

DS: I am the Executive Director of the Biomanufacturing Center at Cedars-Sinai Medical Center, a role I have held for 15 years. I received a Bachelor’s in Chemical Technology and Chemical Engineering from the University of Mumbai and my PhD in Biomolecular Chemistry from the University of Wisconsin-Madison. Shortly after, I moved to Cedars-Sinai Medical Center to establish a team focusing on induced pluripotent stem cell (iPSC) technology, disease modeling, and developing a biorepository.

At the Biomanufacturing Center, the team serves both academic and industry clients, providing contract manufacturing for cell and gene therapy in clinical trials. Additionally, they maintain an iPSC biorepository derived from patient-specific cells for drug discovery and disease modeling purposes.

How do you establish in-process controls and release specifications for specific intermediate cell banks, drug substances, and final drug products?

JR: The requirements for in-process and release testing are significantly different as they serve distinct purposes at various stages. Both are crucial to ensuring the quality and safety of the manufactured product. In-process controls are used to monitor ongoing manufacturing and ensure that critical process parameters (CPPs) remain within defined acceptance criteria.

This aids in the detection of any deviations during cell expansion and allows for real-time adjustments to maintain product consistency. At CBC, several in-process tests are carried out, such as cell morphology assessment, using a proprietary in-house ranking system. The iPSCs have a distinct morphology in vitro, and years of experience allow for the distinction of a good iPSC batch from a poor one simply by examining them under the microscope.

Another key in-process test is the residual reprogramming vector assay. The CBC proprietary iPSC reprogramming technology requires the use of multiple plasmids, which should not be present in the final product cell banks. Therefore, clearance must be ensured during the expansion phase. Further, we have developed a highly sensitive in-house detection assay based on droplet digital PCR (ddPCR), capable of detecting as few as 0.004 copies of the reprogramming vector per cell. This serves as a go/no-go in-process control.

In addition to quality assurance, there is a business aspect to in-process controls, as time in a GMP environment is expensive. Detecting a batch that starts to deviate early allows for its termination so that the focus can remain with resources on compliant batches, therefore avoiding unnecessary expenses in the clean rooms.

On the other hand, final release QC testing is performed at the end of the manufacturing process. A distinction can be made between products that are fresh and those that are cryopreserved. In both cases, the primary goal is to confirm that the manufactured product meets predefined specification—this includes identity, purity, potency, and safety. These tests are mandatory for releasing the final product from the facility. They are specific to each type of final drug product and can vary depending on the materials used in manufacturing, the route of administration, and the mechanism of action.

DS: When it comes to defining in-process control and release specifications for different cell types at various stages, it is crucial to start by identifying the critical quality attributes (CQAs). This can be done through a variety of methods, considering the different cell types that we work with at CBC.

Next, risk assessment tools are employed, such as failure mode and effects analysis, to evaluate the risks associated with each attribute and prioritize them based on their potential impact on the cell bank or final drug product. Further, process mapping is performed, outlining each step in the manufacturing process and identifying parameters that could affect the defined quality attributes or CPPs.

Experiments are then conducted to determine the optimal ranges for those CPPs that would ensure the desired defined quality attribute. Once the experiments are completed and there are defined CQAs and CPPs for all stages, in-process controls are then established. Cell morphology is one example; however, we also measure cell viability at various passages, monitor growth rates, and track population doubling time. If any of these metrics fall outside acceptable ranges, it can be determined if the cell bank meets the go/no-go criteria.

For example, if iPSCs suddenly start dividing more rapidly, it may indicate a genetic abnormality, prompting genetic testing. Additionally, at certain points, potency testing is conducted to verify that the product, whether a cell or final drug product, delivers the intended therapeutic effect.

About our speakers:

DHRUV SAREEN is the founding Executive Director of the Cedars-Sinai Biomanufacturing Center (CBC), West Hollywood, CA, USA and the iPSC Core. He has extensive experience in iPSC-based disease models, GMP biomanufacturing, space medicine, and translating cell therapies to the clinic. The CBC specializes in iPSC and cell/gene therapy manufacturing, including a state-of-the-art cGMP facility for clinical-grade cell production. Dr Sareen established iPSC line and differentiation labs with automation for large-scale production and curated a biorepository with over 1,200 iPSCs. His research focuses on stem cell differentiation into mature cells and building automation pipelines for scaling cell therapies. He holds patents and has published extensively.

JONATHAN RODRIGUEZ is the Manager of the Quality Control Department at the Cedars Sinai Biomanufacturing Center. He completed his Bachelor’s and Master’s degrees in Cell Biology, Genetics, and Pathology at the University of Lyon, Lyon, France. He conducted his doctorate studies and obtained his PhD in Therapeutic Engineering during which he worked on the role of mesenchymal stem cells from adipose tissue to ameliorate skin wound healing. He then decided to pursue his journey abroad and his post-doctoral work focused on limbal stem cells to treat patient suffering from limbal stem cells deficiency in the laboratory of Dr Sophie Deng at the University of California, Los Angeles (UCLA). Dr Rodriguez has extensive experience with human stem cells, molecular biology, process development during pre-clinical studies in a cGMP environment to accelerate stem cell therapies.