Hematopoietic Stem/Progenitor Cells and Engineering: HEMATOPOIETIC STEM/PROGENITOR CELLS (HPC-A) CRYOPRESERVATION PROCESS VALIDATION USING CRYOSTOR CS10 FREEZE MEDIA

ABSTRACT

Background & Aim: During the COVID-19 pandemic, we performed HPC-A cryopreservation process validation using the CryoStor CS10 freeze media to replace the current 10% DMSO cryoprotectant (Control), which encountered severe backorder. Methods, Results & Conclusion(s) This process validation included phase I, phase II, and follow-up studies. Ten HPC-A collection cell product samples were cryopreserved in the phase I study using CS10 and Control (11) post-plasma depletion. Post-thaw viability tests using the 7-AAD method were performed on the cryopreserved samples for parallel comparison. In phase II, each of three patient HPC-A cell products was split evenly into CS10 and Control cryopreservation. The CS10 cryopreserved HPC-A cell products only were used for infusion. The recipients' engraftment outcomes of white blood cells (WBC), granulocytes (ANC), and platelets (Plts) were monitored. Post-thaw viability test was performed on the quality control samples from both groups. In the follow-up study, engraftment outcomes of WBC, ANC, and Plts were evaluated from ten recipients who received the CS10 cryopreserved HPC-A. In the phase I study, the post-thaw viability of the CS10 group was significantly higher than the Control group (p=0.002). All post-thaw viability results were above 60%, the current lab release criteria. In the phase II study, all cryopreserved cell products met cell product release criteria (> 60%). All engraftment results were within our center-established ranges except for the Pt b's platelet engraftment. Three recipients had not had any cell product infusion-related adverse events post infusion. Both CD34 and CD45 post-thaw viability results in the CS10 group were remarkably higher than the Control group, except for the patient c's CD34 viability. In the follow-up study, the total infused cell product volume ranged from 60 ml to 118 ml, and the WBC concentration in the cryopreserved cell products ranged from 134 to 440 (x10