Cell and gene therapies (CGTs) are revolutionizing the treatment of various genetic and life-threatening diseases. These therapies involve altering the genetic makeup of cells or using genetically modified cells to treat conditions, offering hope where traditional therapies have failed. From treating cancer to rare genetic disorders, CGTs have shown immense promise. However, as their development accelerates, a significant challenge emerges in the form of manufacturing. Producing CGTs requires highly specialized infrastructure, precise processes, and significant investments, making the manufacturing landscape both complex and costly.

In this article, we will explore the operational challenges faced by CGT manufacturers and the strategic considerations needed to overcome these hurdles. We will explore the difficulties of scalability, quality control, and infrastructure, as well as the emerging decentralized manufacturing models and the role of technology in addressing some of these challenges.

Specialized Infrastructure and Equipment

One of the most significant challenges in CGT manufacturing is the need for specialized infrastructure and equipment. Unlike traditional biologics or small-molecule drugs, CGTs involve intricate processes such as harvesting cells, gene editing, purification, formulation, and extensive quality control testing. These complex steps require state-of-the-art equipment and highly controlled environments to ensure the safety, efficacy, and purity of the final product.

Manufacturing facilities for CGTs need to comply with Good Manufacturing Practices (GMP), which include strict cleanroom conditions and sophisticated testing protocols. This is to guarantee the purity, sterility, and viability of the cells or gene therapies produced. The costs associated with setting up and maintaining GMP-compliant facilities are staggering. This does not include the substantial ongoing operational costs. Moreover, the high defect rates often encountered in CGT production, which can result from inconsistencies during harvesting, processing, or gene editing, further escalate costs.

These financial challenges can act as a significant barrier, particularly for smaller companies that may lack the capital to invest in such specialized infrastructure. This financial burden could delay the widespread accessibility of CGTs to patients, potentially hindering innovation and slowing the adoption of these life-saving treatments.

Scalability and Reproducibility Challenges

The manufacturing of CGTs faces another major challenge in scalability. As therapies advance and demand grows, companies must determine how to produce therapies at scale while maintaining consistent product quality. Scalability is particularly challenging for autologous cell therapies, where cells are harvested from individual patients, genetically modified, and returned to the patient for treatment. This individualized approach inherently limits economies of scale, and it requires multiple production steps for each patient, which can lead to variability in outcomes.

On the other hand, allogeneic therapies, which use cells from a donor, also present challenges. These therapies can suffer from donor variability, which impacts the consistency of the final product. One promising solution to this issue is the use of induced pluripotent stem cells (iPSCs), which are derived from adult cells and can generate a large supply of cells for treatment. However, even iPSC-based therapies face the hurdle of ensuring consistency across different batches of cells.

The challenges of scalability are compounded by the need for regulatory approval. To receive approval, developers must demonstrate consistent efficacy and safety across batches of products. Achieving reproducibility and quality control as production scales up becomes a significant hurdle.

Key Manufacturing Technologies and Their Challenges

Several critical technologies are central to CGT manufacturing, but each comes with its own set of challenges.

- AAV (Adeno-Associated Virus) and LV (Lentivirus)-based Gene Therapies: AAVs and LVs are viral vectors used to deliver therapeutic genes to patients. While AAVs are preferred for their low immunogenicity and long-term expression, they present challenges in production, particularly in the purification process. Issues like separating empty from full capsids and managing impurities can lead to inconsistent yields and safety concerns. Similarly, LVs, which integrate into the host genome, face contamination risks from helper viruses and require careful optimization to prevent toxicity.

- Mesenchymal Stem Cells (MSCs): MSCs are widely used in regenerative medicine for their ability to target inflamed or injured tissues. However, the manufacturing of MSC-based therapies faces challenges related to donor variability, tissue sourcing, and culture conditions. The need for extensive expansion of MSCs to achieve clinical doses introduces high costs, variability in potency, and concerns over safety, particularly related to the use of fetal bovine serum (FBS) in culture media.

- CAR-T Cell Therapies: CAR-T cell therapies involve modifying a patient’s T cells to target cancer cells. These therapies require precise and meticulous manufacturing processes, particularly around the quality of the starting material (leukapheresis) and the effectiveness of the gene modification. One of the significant challenges in CAR-T manufacturing is optimizing the "vein-to-vein" time—the time from collecting the patient’s T cells to administering the modified cells. Reducing this time is critical for improving patient outcomes, especially in urgent cancer treatments.

Overcoming Capacity and Resource Constraints

Despite the growing demand for CGTs, the manufacturing capacity remains limited. Fewer than ten sites worldwide currently have the capacity to produce these therapies at scale. This capacity constraint leads to slower approval processes and delays in meeting patient demand. Pharma companies are increasingly partnering with contract development and manufacturing organizations (CDMOs) to scale up production, ensuring faster delivery and improved capacity management.

Autologous therapies, in particular, are challenging due to their personalized nature. Meeting the complex and lengthy manufacturing timelines required for these therapies often leads to the production of out-of-specification products, which could introduce safety, efficacy, and regulatory issues.

The Future of Manufacturing: Centralized vs. Decentralized Models

The debate between centralized and decentralized manufacturing models continues to be a key focus in the CGT industry. Centralized manufacturing has the advantage of standardization, which can improve product consistency and regulatory compliance. However, it also comes with longer delivery times and significant logistical challenges.

Decentralized manufacturing, on the other hand, promises faster delivery and improved access for patients, especially for therapies like CAR-T, which require rapid administration. In-house GMP facilities within hospitals or localized facilities are gaining traction, but they come with the challenge of high setup costs and regulatory complexities.

Ultimately, the solution may lie in a hybrid approach, where centralized and decentralized models complement each other to balance efficiency and flexibility.

Technological Innovations and Automation

Automation and digitalization hold significant promise in addressing the operational challenges of CGT manufacturing. By automating key processes, manufacturers can reduce the risk of contamination, improve consistency, and increase throughput. Automation also allows for faster and more accurate data processing, which can expedite regulatory approvals.

Digital technologies, including electronic batch records and data-driven solutions powered by machine learning and AI, can enhance production processes by identifying inefficiencies, improving quality control, and enabling real-time monitoring of manufacturing operations.

The Path Forward

Cell and gene therapies hold immense promise in treating genetic diseases, offering hope for conditions previously considered untreatable. However, the manufacturing complexities associated with CGTs remain a significant barrier to their widespread clinical application. Overcoming challenges related to scalability, quality control, infrastructure, and resource limitations is essential for advancing CGTs from potential to practical treatments.

As the industry moves forward, innovations in manufacturing technology, flexible manufacturing models, and increased collaboration between industry players, regulators, and stakeholders will be crucial. By addressing these challenges, the CGT sector can achieve greater efficiency, reduce costs, and make these life-saving therapies more accessible to patients worldwide.

References

1.Lee NK, Chang JW. Manufacturing Cell and Gene Therapies: Challenges in Clinical Translation. Ann Lab Med. 2024;44(4):314-323.

2.Zhuang WZ, Lin YH, Su LJ, et al. Mesenchymal stem/stromal cell-based therapy: mechanism, systemic safety and biodistribution for precision clinical applications. J Biomed Sci. 2021;28(1):28.

3.PwC Belgium. Cell and gene therapies. How to overcome manufacturing challenges. PwC. Published 2023. Accessed December 10, 2024. https://www.pwc.be/en/news-publications/2023/how-to-overcome-manufacturing-challenges.html

4.Pharmaceutical Technology. The future of cell and gene therapy manufacturing. Pharmaceutical Technology. Published October 6, 2023. Accessed December 10, 2024. https://www.pharmaceutical-technology.com/features/the-future-of-cell-and-gene-therapy-manufacturing/

About the Author:

Neeta Ratanghayra

Freelance Medical Writer

Neeta Ratanghayra is a freelance medical writer, who creates quality medical content for Pharma and healthcare industries. A Master’s degree in Pharmacy and a strong passion for writing made her venture into the world of medical writing. She believes that effective content forms the media through which innovations and development