Manufacturing Process Intensification for Pluripotent Stem Cell-Derived Rare Red Cell Production

Project Summary/Abstract The goal of this Phase I STTR proposal is to manufacture designer red blood cells (RBCs) from a renewable source of pluripotent stem cells in an economically intensified and scalable platform for distribution to relevant US laboratories to be used as reagents in the identification of antibodies for patients requiring blood transfusion. A common complication of chronic RBC transfusion therapy is alloimmunization, or the formation of alloantibodies in response to antigens (proteins) present on the surface of donor RBCs that the recipient lacks. Patients with sickle cell disease (SCD) are particularly at risk due to genetic variants in the Rh blood group system. Alloimmunization has severe clinical consequences including high morbidity, delays in identifying compatible blood, and delayed hemolytic transfusion reactions (DHTR) with worsened anemia. Identification of the precise antibody target is critical for selection of donor units, transfusion effectiveness, and safety. The Chou Laboratory (CHOP) combined human induced pluripotent stem cell (iPSC) and gene-editing technologies to create a renewable source of cells with unique Rh profiles that facilitate the identification of complex Rh antibodies. Donor-derived RBCs with these rare antigen profiles are currently available to only a few laboratories and in very limited quantities. CHOP demonstrated that the RBCs derived from iPSCs (iRBCs) are compatible with standard laboratory assays and can help determine the precise Rh antibodies in patient plasma. Safi Biotherapeutics Inc (Safi) is a pre-clinical blood cell therapy company that has developed a cost-efficient and scalable bioprocess for manufacture of human RBCs from hematopoietic stem cells. Safi’s manufacturing expertise in stem cell-derived blood manufacture will be leveraged to design and demonstrate a process for bulk manufacture, downstream process/formulation, and distribution of the iRBCs. This work will be accomplished in two aims. The first will optimize RBC production from human iPSCs using economically intensified and scalable technologies, and the second will validate the performance of the different product formulations in routine antibody identification assays using patient samples. This work will define the process necessary to generate sufficient quantities of iRBCs with specific Rh profiles and support the development of a phase II proposal to scale up manufacture in preparation for commercialization of in vitro grown RBC reagents.