The Safety and Efficacy of a CRISPR/Cas9-Engineered Universal CAR-T Cell Product (CTA101) in Patients with Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia

作者：Yongxian Hu, Yali Zhou, Mingming Zhang, Wengang Ge, Yi Li, Li Yang, Guoqing Wei, Lu Han, Hao Wang, Xingwang Zhang, Jiangtao Ren, He Huang · 发表于：Blood · 年份：2020 · DOI：10.1182/blood-2020-142262 · 被引用次数：15 · 研究领域：CAR-T cell therapy research、CRISPR and Genetic Engineering

Introduction Although autologous CAR-T therapy targeting CD19+ B-cell has proven efficacy in hematological malignancies. The challenges such as undesirable waiting time, possible manufacturing failures and high cost, remain to be solved. In addition, antigen-loss/downregulation leads to treatment failure after single-target CAR-T therapy. To tackle these issues, we developed a universal CD19/CD22-targeting CAR-T cell with the TRAC region and CD52 gene disrupted using CRISPR/Cas9 technology. Pre-clinical data demonstrated the safety of CRISPR gene editing and the anti-leukemia ability of CTA101. Method Pts with CD19+ or CD22+ r/r B-ALL received a single dose of CTA101 with traditional 3+3 dose escalation (dose level: 1, 3 and 6×106 CAR+ T cells/kg). Prior to CTA101 infusion, pts received pre-conditioning chemotherapy regimen consisting of cyclophosphamide, fludarabine and alemtuzumab. The primary endpoint is the frequency of DLTs and AEs and secondary endpoints including ORR, OS, cellular PK, etc. (NCT04227015) Results Characteristics of CTA101 CTA101 was manufactured by electroporation of ribonucleoprotein complexes (RNP) comprising Cas9 loaded with sgRNA targeting TRAC and CD52 followed by lentiviral transduction of the CAR transgene. All products were expanded above 100-folds after 10-12 days manufacturing (Fig.1a). CAR expression was detected by FCM staining, ranging from 40~80% (Fig.1b). The frequency of editing as determined by flow cytometry was consistently above 85% (...