Experience in manufacturing a haploidentical biomedical cell product enriched with regulatory T-lymphocytes

Abstract

Graft-versus-host disease (GVHD) remains the main life-threatening immunologic complication of hematopoietic stem cell transplantation. Despite modern pharmacological approaches for preventing and treating GVHD, there remains a need for new approaches to cure GVHD. Currently, more and more clinical experience is emerging globally in the field of using regulatory T-cell (Treg) therapies for the treatment of refractory GVHD. Manufacturing cell products for Treg therapies has a wide range of protocol variations. We have developed an approach of Treg manufacturing for cell therapy and present data from our experience in manufacturing a haploidentical Treg cell product by combining CD25+ immunomagnetic selection with closed system flowbased cell sorting methods. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. The study describes the processes of producing 9 Treg cell products. According to the manufacturing protocol described here, it is possible to obtain a cell product that meets the quality control requirements necessary for approval for clinical use. Quality control includes the assessment of the cell composition, viability, and microbiological safety of the product, and is performed at all major stages of production. The final cell product is characterized by consistently high levels of FoxP3-expressing Treg (median: 98%), with a median cell viability of 99.1%, and has a high potential for functional efficacy. Thus, the protocol for producing Treg cell products by combining CD25+ immunomagnetic selection with flow cytometry-based cell sorting methods can be used for the clinical treatment of GVHD.