A Monte Carlo framework for managing biological variability in manufacture of autologous cell therapy from mesenchymal stromal cells therapies

Abstract

Manufacturing processes for autologous cell therapy need to reproducibly generate in specification (quality and quantity) clinical product. However, patient variability prevents the level of control of cell input material that could be achieved in a cell line or allogeneic-based process. We have applied literature data on bone mar-rowÀderived mesenchymal stromal cells variability to estimate probability distributions for stem cell yields given underlying truncated normal distributions in total nucleated cell concentration, stem cell percentage and plausible aspirate volumes. Monte Carlo simulation identified potential variability in harvested stem cell number in excess of an order of magnitude. The source material variability was used to identify the proportion of donor manufacturing runs that would achieve a target yield specification of 2E7 cells in a fixed time window with given proliferative rates and different aspirate volumes. A rapid, screening, development approach was undertaken to assess culture materials and process parameters (T-flask surface, medium, feed schedule) to specify a protocol with identified proliferative rate and a consequent model-based target aspirate volume. Finally, four engineering runs of the candidate process were conducted and a range of relevant quality parameters measured including expression of markers CD105, CD73, CD44, CD45, CD34, CD11b, CD19, HLA-DR, CD146 (melanoma cell adhesion molecule), CD106 (vascular cell adhesion molecule) and SSEA-4, specific metabolic activity and vascular endothelial growth factor secretion, and osteogenic differentiation potential. Our approach of using estimated distributions from publicly available information provides a route for data-poor earl-stage developers to plan manufacture with defined risk based on rational assumptions; furthermore, the models produced by such assumptions can be used to evaluate candidate processes, and can be incrementally improved with accumulating distribution understanding or subdivision by new process variables.

Thymidylate synthase disruption to limit cell proliferation in cell therapies

“…The use of hiPSC offers several advantages over mesenchymal and embryonic stem cells (MSC and ESC, respectively). HiPSCs circumvent ethical concerns associated with the embryo derived ESCs ( 8 , 9 ). Unlike donor-derived MSCs and ESCs, hiPSCs’ patient-specificity minimizes the risk of immune rejection and graft-versus-host disease ( 10 , 11 ).…”

Process analytical technologies in cell therapy manufacturing: State‐of‐the‐art and future directions

“…[ 19 ] MSCs are promising cell therapies that have been widely demonstrated in clinical trials for treating a range of diseases, [ 20 ] although their therapeutic efficacy remains unproven due to variables such as biological factors (e.g., age, sex, ethnicity), [ 21 ] dosage, [ 22 ] route of delivery, [ 23 ] tissue source (e.g., bone marrow, adipose, umbilical cord), [ 24,25 ] and manufacturing processes. [ 26 ] Ongoing advancements in science and technologies will continue to address the various aspects of improving autologous and allogeneic cell therapies. Herein, we provide a short overview of cell therapy manufacturing processes and review process analytical technologies (PAT) that are employed to advance cell therapy manufacturing.…”