Dr. Patrick Hanley, assistant research professor of pediatrics in the Center for Cancer and Immunology research at the Children’s Research Institute in Washington D.C. and director of the Good Manufacturing Practices cell therapy laboratory at Children’s National Health System, on the new developments in the design and manufacturing for T cell therapies. He discussed ways in which technology can help simplify the methodologies and bring consistency and scalability to cell manufacturing.
Patrick Hanley, PhD, assistant research professor of pediatrics in the Center for Cancer and Immunology research at the Children’s Research Institute in Washington DC and director of the Good Manufacturing Practices (GMP) cellular therapy laboratory at Children’s National Health System, talked to writer Tanuja Koppal, Ph.D., about the new developments in the design and manufacturing for T cell therapies. He discussed ways in which technology can help simplify the methodologies and bring consistency and scalability to cell manufacturing.
Tanuja Koppal: How do you envision the development of T cell therapies, particularly in terms of overcoming some of the existing challenges?
Patrick Hanley: I can certainly comment on this from a manufacturing perspective, as I am the director of our cell manufacturing facility. We now have a new model for developing therapies for patients. No longer do we use the typical pharmaceutical model where you have one lot of Tylenol that everyone takes. We are now looking at personalized therapies where you have one drug for one patient and logistically that can be quite challenging. As we move forward in this direction we have to simplify the process so that we don’t require an entire clean room for every product that is being manufactured. We have all these new exciting therapies but how to get them to all the patients that need them, with all the space, time and logistical requirements, is still the biggest bottleneck.
TK: Your recent paper discussed the need to integrate automated technologies to improve consistency and scalability in cell manufacturing. Will that help?
PH: Even five years ago the cells for therapeutic use were generated in tissue culture flasks or plasticware. With the advent of commercialization the manufacturing transitioned to bioreactors or closed systems, and people started looking at the quality attributes that were needed for manufacturing these cells. In the case of chimeric antigen receptor (CAR) T cells, it was important to find out what the starting product looked like and what was the phenotype of cells going in. Each of us has a different percentage of T cells in our body and for manufacturing purposes certain cell population of interest might need to be enriched. So that’s one way of improving the final output. Putting cells into an automated bioreactor system where they can be generated from start to finish is another option. Making the process more automated will certainly enable us to get more consistent products and treat more patients.
TK: Are T cells particularly challenging to work with?
PH: T cells in some ways can be more difficult to modify, either because they grow in suspension or they are averse to changes. Adherent cells can be easier to genetically manipulate. For T cells, we have to use lentivirus or retrovirus, as opposed to electroporation to transfect the cells. You can use electroporation with T cells but it’s not easy. While some cell types like mesenchymal stromal cells (MSCs) can be very uniform and homogenous, the starting peripheral blood mononuclear cell population, which contains T cells, is very diverse. With T cells, you have CD4, CD8 and different types of memory cells and we are still trying to figure out how important they all are.
TK: Can you talk about the simplified method that you have developed to manufacture T cells which appears in another recent paper.
PH: This paper refers to the use of umbilical cord blood (CB)-derived T cells, and to my knowledge we may be the only lab in the world that delivers these virus-specific T cells derived from CB to patients. Even though there is an unmet need, people don’t take the time or effort to use these cells because they are so difficult to manipulate. Cord blood transplant is used in the same way as bone marrow transplantation, but because the cells are mostly naïve and because there are typically fewer stem cells in the transplant product there is an increased risk for viral infection. The challenge for our group has been that it has taken us two to three months to make these cells. What we do now is use activated T cells and pulse those activated cells with peptide, which brings down time for manufacturing from three months to 30 days.
Read More about cell therapies on AABME.org
TK: Where do you see the field headed in the next few years?
PH: Many of us are trying to go in the direction where you can use off-the-shelf T cell products from a cell bank, where they have one product per patient. However, CAR T cells are autologous, where you have to extract them from a patient, modify and grow them and give them back to the same patient. We are still scaling out instead of scaling up. There are bioreactors than can scale up to one to five billion cells, but we still don’t have systems that can grow up to a trillion cells. So, we have to use 200 bioreactors or 200 different runs to scale the production. There is a lot of room for collaboration between cell therapy and manufacturing experts and engineers to create useful systems and cell-specific bioreactors to improve production. If we can combine all our expertise we can make advances, just like the small molecule and antibody fields have done over the past 30 years. We have just started out in cell therapy and it’s going to look very different five to 10 years from now with all the technological advances that have yet to come.
Tanuja Koppal, PhD is a freelance writer based in Randolph, NJ.