Demethylating agents in combination with CD7-targeted CAR-T for the successful treatment of a case with mixed-phenotype acute leukemia relapsed after allogeneic hematopoietic stem cell transplantation: A Case Report

• Published in: Frontiers in immunology 2023-09, Vol.14
• Main Authors: Han, Ying, Yao, Hao, He, Guang-cui, Lai, Si-han, Deng, Yan, Zhang, Shan, He, Ying, Xiong, Yi-song, Chang, Alex H., Su, Yi, Yi, Hai
• Format: Article
• Language: English
• Subjects: allogeneic hematopoietic stem cell transplantation; CD7-targeted; chimeric antigen receptor-t cell therapy; demethylate; demethylating agent; Immunology; mixed-phenotype acute leukemia
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2023.1254010

BackgroundAllogeneic hematopoietic stem cell transplantation (allo-HSCT) has cured many patients with malignant hematologic diseases such as mixed phenotype acute leukemia (MPAL), while those relapsing after allo-HSCT still exhibit high mortality, poor prognosis, and no standard treatment modalities. It is necessary to explore more therapeutic modalities for patients with post-transplant relapse to obtain a better prognosis.Case presentationIn this case report, a young male with MPAL received allo-HSCT after reaching complete remission (CR) by induction chemotherapy. Unfortunately, relapse of both myeloid and T lineages occurred nine months later. After receiving demethylating chemotherapy, myeloid lineage measurable residual disease (MRD) turned negative. T-lineage MRD turned negative after CD7-targeted chimeric antigen receptor (CAR)-T cell therapy. The bone marrow remained MRD-negative for 4 months. This case preliminarily demonstrated a long-lasting CR with CD7-targeted CAR-T cell therapy, allowing a better prognosis.ConclusionDemethylating drugs combined with CD7-targeted CAR-T cell therapy is feasible in treating MPAL patients with relapse after transplantation, with good efficacy and safety, which will be a promising treatment option for MPAL.