In the past few years, the field of cell and gene therapy has witnessed major breakthroughs. It has become one of the hottest fields in the biotech industry, with the hope that it will eventually revolutionize the way we treat diseases and, ultimately, become a mainstream treatment option.
Cell therapy refers to the transfer of healthy or modified human cells to heal or replace damaged tissue or cells, while gene therapy refers to the modifying of genes or replacing of defect genes with healthy ones to treat, cure or prevent a disease or medical condition. Though distinct, the two are closely associated with each other and often considered one field.
Though still in their infancy, cell and gene therapies are developing at an explosive rate. There are currently hundreds of related programs in the clinic. This means that, over the next several years, many cell and gene therapies are likely to enter the market.
There are clearly good prospects for the future of cell and gene therapy, but the road ahead contains obstacles as well. These include a prolonged and dynamic R&D cycle, safety issues, and manufacturing cost and limitations. Only by addressing and overcoming these challenges can we unleash the full potential of cell and gene therapy to help patients in need.
Dr. David Chang, CEO of WuXi ATU, WuXi AppTec’s cell and gene therapy Contract Development and Manufacturing Organization (CDMO), recently sat down with the WuXi AppTec Content Team to share his observations on cell and gene therapy’s current development and insights into the field’s path forward.
Prior to joining WuXi AppTec, Dr. Chang held senior positions at several leading companies, such as Celgene (acquired by Bristol-Myers Squibb in 2019) and Genentech. He also has extensive experience in the biotech and cell and gene therapy industries.
What’s the current state of cell and gene therapy globally?
Dr. Chang: Although the earliest research occurred decades ago, it is only in recent years that we have been able to bring effective therapies to the market.
The biggest and by far most famous breakthrough in cell therapy is of course CAR-T (Chimeric Antigen Receptor T-Cell Immunotherapy). In 2017, Novartis’ Kymriah, developed for the treatment of certain types of ALL (acute lymphoblastic leukemia) patients, and Yescarta, developed by Gilead’s Kite Pharma for large B-cell lymphoma, were successively approved by FDA.
These approvals demonstrated the potential of such therapies for cancer treatment. Gene therapy has also been gaining momentum for a long time, and over the past five years several drugs have been approved by regulators in Europe and the U.S. to treat severe inherent genetic diseases caused by specific genetic mutations, such as spinal muscular atrophy (SMA) and β-Mediterranean anemia.
These recent developments are a great encouragement to the industry— to drug developers, to investors, and of course they are tremendously encouraging to patients as well. Keep in mind that, for any new therapy, a breakthrough from zero to one is the hardest.
Given these successes, it’s no surprise that enthusiasm for cell and gene therapy has grown significantly lately, with many innovative companies being involved. The current pace of development is explosive. Hundreds of drugs are in the pipelines around the world, and many of them are already in the late clinical stage.
To what extent will these types of therapies change the future of medicine?
Dr. Chang: Cell and gene therapies have enabled people to effectively treat and even cure hitherto very difficult-to-treat cancers and rare genetic diseases, thus rewriting the life stories of many patients. I believe that they will become one of the mainstream treatments in the future.
Cell therapy has the potential to be one of the most important treatments in our fight against cancer. For example, current CAR-T therapies have proven effective in treating relapsed/refractory ALL. These specific CAR-T therapies can, in theory, be applied to treat a lot of other cancers, and there’s a lot of relevant research going on right now.
As for gene therapy, it has been applied to treat a wide range of diseases, such as cardiovascular disease, eye diseases, nervous system diseases, metabolic diseases and solid tumors, in addition to long-standing efforts in genetic blood diseases such as sickle cell disease and hemophilia.
For cell and gene therapy to really take off, what challenges and problems need to be tackled?
Dr. Chang: The potential is huge, but the challenges should not be underestimated. To keep our forward momentum there are still a series of bottlenecks to overcome. The industry needs to continuously improve R&D pipeline and lifecycle management, optimize the relevant manufacturing and logistics processes, and reduce costs.
I personally believe the major bottleneck is not in R&D, but rather in manufacturing as well as in test and release. One of the major issues to consider in cell and gene therapy is how to scale out or up the manufacturing while reducing the cost at the same time.
So, what exactly are the manufacturing challenges for cell and gene therapy?
Dr. Chang: In gene therapy, there is a big gap in the production of non-replicable lentiviral vectors and AAV vectors. Depending on the genes of interest, production sometimes requires large-scale fermentations to meet a single patient’s treatment needs, making it commercially challenging or even infeasible. Therefore, yields and efficiency of virus vectors manufacturing are a major challenge for the whole industry.
Cell therapy also faces the limitations in commercial manufacturing. Autogenous cell therapy is an individualized treatment that activate, modify and expand the patient’s own immune cells, so a single batch is made for one patient only. This means that the manufacturing scale will never be as large as that of traditional small-molecule or biologics products, and thus is much more costly.
At the same time, cell therapy, especially allogeneic cell therapy, which utilizes donor cells, faces the challenge of graft-vs-host disease. It’s necessary to ensure that the modified cells transmitted back to the patient do not generate an immune response (similar to what happens with organ transplant rejection).
Finally, cell therapy faces strict requirements for timely and reliable transport of labile raw material and cell products, as well as complexity in product testing and release.
As an enabling platform for gene and cell therapy, what solutions and advantages does WuXi ATU have to address these challenges?
Dr. Chang: Through the establishment of an advanced therapies CDMO platform, we offer real one-stop service to our partners to help with their research, manufacturing, and test and release.
Most existing CAR-T manufacturing processes are not closed and thus require substantial open, manual manipulation under a biosafety hood, which may lead to errors, high costs, and risk of contamination. To specifically address these problems, WuXi ATU has recently introduced an advanced closed automated CAR-T platform in its base in Philadelphia to meet the manufacturing needs of our partners.
Relying on our two bases respectively in the US and China, we can not only meet the diverse manufacturing needs of customers from different regions, but also ensure the timeliness of transportation that CAR-T requires.
In gene therapy manufacturing, currently, we have established high-yield, highly scalable AAV and lentiviral platforms which can supply cost-effective and commercially feasible viral vectors in a timely manner.
WuXi ATU also has the capability to provide international standard oncolytic virus product development and manufacturing services to customers worldwide. In November, we signed a strategic partnership agreement with Gene Medicine, a Korean gene therapy biotech, to provide services covering oncolytic virus product development, manufacturing and clinical trials for its key programs.
In addition to the mainstream approaches of introducing genes into cells, we are also establishing more efficient and promising non-viral technologies such as electroporation, which utilizes electric fields to allow genes to pass through the cell membrane.
Most importantly, WuXi ATU also provides the integrated analytical method development and testing services to our manufacturing clients. With the complexity of testing and releasing advanced therapies products in a timely and reliable manner, this integrated testing and releasing service will greatly support our clients to supply their products to meet either clinical or commercial needs.
Through improving efficiency and reducing costs, we’ll support our clients to enhance the accessibility of cell and gene therapy – and help more of our partners’ innovative therapies to reach patients as broadly as possible as soon as possible.
The rapid development of cell and gene therapy has attracted a lot of outside attention. People have high expectations. From the perspective of someone on the inside, what do you see when you look at the near future?
Dr. Chang: There is no denying that cell and gene therapy still face challenges. Actually, every new therapy faces or faced a similar situation. Even regulators need to learn alongside industry. This process is both normal and necessary. I believe that in another five to ten years, with the accumulation of relevant knowledge and experience, the whole industry will become more mature, efficient and standardized.
I firmly believe that the future for cell and gene therapy is very bright, and WuXi ATU stands ready to join hands with global innovators to move it to the next stage.