EHA 2021丨 BriSTAR Immunotech Limited releases the latest data on CD19/CD20 Dual STAR-T Therapy R/R B-ALL
The 26th Annual Conference of the European Hematology Association (EHA) is convened as scheduled (June 9-17). As the largest-scale international conference in the field of Hematology in Europe, it attracts tens of thousands of professionals from more than 100 countries around the world every year, bringing together the world's most cutting-edge clinical research achievements. Only after strict screening and selection will the research achievements be presented at the conference.
The "Innovative CD 19/CD 20 Dual STAR-T Cell Therapy for the Treatment of Refractory/ Relapse (R/R) Acute B-Lymphocyte Leukemia (R/R B-ALL)" jointly launched by Bristar Immunotech Limited with Ludaopei Hospital is honored to be one of the few studies selected in the special report of the EHA conference.
The Synthetic TCR and antigen receptor (STAR) is an innovative chimeric antigen receptor structure jointly developed by Bristar Immunotech Limited and Tsinghua University. With T cell receptor (TCR) as the basic framework, it has been functionally transformed, with its variable region replaced with one or more single chain antibody (scFv) fragments to form a new antigen receptor structure. The basic research results of this structure have been published in the Science Translational Medicine of this year.
The data reported at the EHA conference are the early clinical research results of STAR-T products targeting CD19 and CD20 for the treatment of recurrent/ refractory B-ALL. The study was conducted in Hebei Yanda Ludaopei Hospital. A total of 10 patients with CD19+ and/ or CD20+ R/R B-ALL were enrolled. The median age of the enrolled subjects was 23 years old, and the tumor load ranged from 0.5% to 53%. Nine subjects were successfully transfused with D19/CD20 Dual STAR-T cells and completed follow-up visits.
In terms of clinical efficacy, 8 patients (8/9, 88.9%) quickly achieved complete response (CR) with negative minimal residual disease (MRD) on day 14 after cell infusion. In addition, the efficacy evaluation results on day 28 showed that 8/9 patients still demonstrated complete response (CR), among whom 6 (6/8) subjects were treated with bridged hematopoietic stem cell transplantation (HSCT), and responses were observed to last for up to 380 days. Among the 2 subjects not treated with bridged allogeneic hematopoietic stem cell transplantation, one subject became positive MRD 30 days after the transfusion with low-dose cells, and died of recurrent infection (prior HSCT) on day 45. However, the recurrence free survival (RFs) of another subject reached 218 days after the transfusion with high-dose cells.
In terms of safety, no grade 3 severe cytokine release syndrome (CRS) or above was observed. Seven subjects developed grade I CRS, and 1 subject presented grade III immune cell-related neurotoxicity (ICANS).
The results of this study suggested that CD19/CD20 Dual STAR-T cells demonstrated high safety and good clinical efficacy in the subjects with R/R B-ALL, and the long-term clinical efficacy was to be confirmed by larger-scale of clinical researches.