2023 Volume 60 Issue 2 Pages 120-124
[Background] TCF3::HLF-positive acute lymphoblastic leukemia (ALL) is consistently resistant to conventional chemotherapy, whereas the efficacy of the graft-versus-leukemia (GVL) effect has been suggested. Recently, allogenic hematopoietic cell transplantation (allo-HCT) following blinatumomab has been reported to induce durable remissions in patients with TCF3::HLF-positive ALL. [Case] A 13-year-old female with a chief complaint of subcutaneous hemorrhage was diagnosed with TCF3::HLF-positive ALL. Although hypercalcemia and disseminated intravascular coagulation worsened owing to tumor lysis, remission induction therapy with aggressive supportive care resulted in complete remission, and minimal residual disease (MRD) was less than 10–4. The patient became MRD-negative after one course of blinatumomab as a consolidation therapy. The transplantation of bone marrow from her HLA 5/8 allele-matched father was performed after conditioning with 12 Gy total body irradiation and etoposide 1.8 g/m2. For graft-versus-host disease (GVHD) prophylaxis, post-transplant cyclophosphamide (PTCy) was used. Although she developed bronchiolitis obliterans, for which she is currently under treatment, she has been disease-free for more than two years after allo-HCT. [Discussion] Haploidentical HCT with PTCy did not increase the risk of relapse or GVHD in adults with ALL, suggesting that PTCy was an effective GVHD prophylaxis without attenuation of the GVL effect. Haploidentical HCT with PTCy in deep molecular remission after consolidation therapy with blinatumomab appears to be a promising strategy for TCF3::HLF-positive ALL.
