ABSTRACT
Background & Aim: A consortium of leading human mesenchymal stem/stromal cell (hMSC) therapy developers, Sentien Biotechnologies, GenCure Biomanufacturing and RoosterBio, are developing a large-scale hMSC biomanufacturing process with a deep Quality focus, culminating in a potency assay qualified with human clinical samples. Methods, Results & Conclusion: A Xeno-Free (XF), fed-batch, microcarrier-based bioreactor process for hMSC manufacturing had been developed and optimized [1], and scaled to a 50L process, with demonstrated comparability between the hMSC critical quality attributes (CQAs) from the bioreactor process and from 2D control cells of similar population doubling (PDL) [2]. Based on this previous process development, GenCure and RoosterBio are leading the first stage of biomanufacturing through upstream (2D seed train & bioreactor expansion) and downstream process (continuous counterflow centrigufation, formulation & fill, and cryopreservation). Bioreactor runs at the 50 L scale were performed using the most commonly used hMSC sources in regenerative medicine: bone marrow (BM-MSCs), umbilical cord (UC-MSCs) and adipose (AD-MSCs). Critical process parameters (CPPs) are defined and critical quality attributes (CQAs) of the harvested cell product are characterized. An initial production run produced over 33billion BM-MSCs that passed the ISCT minimal criteria for MSCs. The subsequent expansion of UC- and AD-MSCs will be presented. Sentien's proprietary platform was used to ask questions on how the MSCs reacted to different stimuli with results showing that BM-MSCs were able to sense and respond with different secretomes to inflammatory stimuli. Our data also showed that BMMSCs induced changes in CD4, CD8 and CD19 cells and significantly reduced TNF-a levels in activated PBMCs, demonstrating their immunomodulatory capabilities. The same assays will be performed using the resulting MSCs from umbilical cord and adipose tissue expanded in the 50L bioreactor. Sentien, which has treated 16 subjects with acute kidney injury (AKI, open IND) and is currently running a trial in severe COVID-19 patients with AKI, will contribute biomarker data from the clinical-scale bioreactor and patient samples. Testing the in vitro developed potency hypothesis against the clinical samples will form the basis of a true potency assay. Through this work, the consortium will develop a generalized quality framework for large scale MSC manufacturing and potency assay development for broad use in regenerative medicine.
ABSTRACT
Background: Coronavirus disease 19 (COVID-19), caused by SARS-CoV-2 was declared a pandemic in March 2020 and remains without any approved treatments. After entering the cells, the virus begins to replicate and viral antigen is presented to antigen presenting cells (APCs), the cells that stimulate the body's normal anti-viral immune response. In severe cases however, this immune reaction becomes dysregulated as evidence by high levels of certain cytokines and chemokines in the blood, a reaction known as cytokine storm. This results in a systemic uncontrolled inflammatory state that triggers a violent attack by the immune system to the body, causes acute respiratory distress syndrome (ARDS) and multiple organ failure, leading to death. Methods: Mesenchymal stromal cells (MSCs) are a unique source of secreted factors that modulate an inflammatory response and enhance the repair of injured tissue. MSCs have been extensively studied in ARDS and other acute organ injuries. Sentien has created a novel delivery approach to enable sustained exposure to MSCs and their secreted factors, overcoming limits of cell transplantation/infusion while preserving their broad acting and dynamically responsive properties. Our lead product, SBI-101, contains allogeneic human MSCs inoculated into a hollow-fiber hemofilter, which enables communication with patient blood via the semi-permeable membrane, while maintaining MSC viability. Through this interplay, SBI-101 aims to restore balance to the immune system by reprogramming the molecular and cellular components of blood in patients with severe inflammation and organ injury. Results: Sentien's Phase I/II clinical study of SBI-101 in critically ill patients with Dialysis-Requiring Acute Kidney Injury (AKI-D) has produced data to support the therapeutic hypothesis of SBI-101. Consistent with MSC biology, inflammatory markers, such TNFa and IFNg, were shown to be modulated, suggestive of a shift from a pro- to an anti- inflammatory state in treated patients. Conclusions: Data obtained in our AKI-D trial showed modulation of many biological molecules and immune populations that may be correlated with severe COVID-19 immunopathology. Here we make the case, using our existing AKI-D trial data, that SBI-101 may be of therapeutic benefit to severe cases of COVID-19.