Blinatumomab 是一种 CD19/CD3 双特异性 T 细胞接合剂，被认为是治疗复发性 B 细胞前体急性淋巴细胞白血病 (BCP-ALL) 的有效免疫疗法。然而，博纳吐单抗在造血干细胞移植（HSCT）后维持治疗中的有效性和安全性尚未确定。一名患有 BCP-ALL 的 5 岁男性患者在维持治疗期间出现骨髓复发。采用 UK-R3 方案进行再诱导治疗后，仍保留 2.3% 的母细胞。然后给予blinatumomab，他实现了微小残留病（MRD）阴性完全缓解（CR）。经过两个周期的 blinatumomab 治疗后，他接受了人类白细胞抗原 (HLA) 匹配的兄弟姐妹的同种异体骨髓移植 (BMT)，并接受全身照射、依托泊苷和环磷酰胺进行调理。开始两个周期的博纳吐单抗维持治疗以防止复发。移植物抗宿主病 (GVHD) 或其他严重不良事件没有恶化。 BMT 后 CR 维持>22 个月。 t 分布对称邻域嵌入 (tSNE) 分析显示，与 HSCT 前使用一样，blinatumomab 改变了 CD8 群体，并显着降低了 CD8 19dim /CD8 CD19- 比率（即幼稚淋巴细胞优势）。 HSCT 后的博纳吐单抗维持治疗可能被认为是一种安全的治疗方法。版权所有 © 2024，Abematsu 等人。

Blinatumomab, a CD19/CD3 bispecific T-cell engager, is recognized as an effective immunotherapy for relapsed B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, the efficacy and safety of blinatumomab in post-hematopoietic stem cell transplantation (HSCT) maintenance therapy has not been established. A 5-year-old male patient with BCP-ALL suffered a relapse in his bone marrow during maintenance therapy. After re-induction therapy with UK-R3 regimen, 2.3% of the blasts remained. Then the blinatumomab was administered, and he achieved minimal residual disease (MRD)-negative complete remission (CR). After two cycles of blinatumomab, he underwent allogeneic bone marrow transplantation (BMT) from his human leukocyte antigen (HLA)-matched sibling, following conditioning with total body irradiation, etoposide, and cyclophosphamide. Two cycles of blinatumomab maintenance therapy were initiated to prevent relapse. There was no exacerbation of graft-versus-host disease (GVHD) or other severe adverse events. CR was maintained for >22 months after BMT. A t-distributed symmetric neighbor embedding (tSNE) analysis revealed that blinatumomab altered the CD8+ population, as with pre-HSCT use, and markedly reduced the CD8+19dim+/CD8+CD19- ratio (i.e., naïve lymphocyte predominance). Blinatumomab maintenance therapy after HSCT may be considered a safe treatment.Copyright © 2024, Abematsu et al.