G-CSF-combined conditioning in allogeneic transplantation for non-remission acute myeloid leukemia with inv(3)(q21q26.2)/t(3;3)(q21;q26.2).

Acute myeloid leukemia (AML) with inv(3)(q21q26.2) or t(3;3)(q21;q26.2) has a dismal prognosis and poor response to conventional chemotherapy. Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative treatment for adult AML with inv(3)/t(3;3) during complete remission (CR). Nevertheless, because fewer than half of patients achieve a CR with induction conventional chemotherapy, allogeneic HCT is frequently performed for AML with inv(3)/t(3;3) in non-remission. Here, we report six patients with adult AML with inv(3)/t(3;3) in non-remission who underwent allogeneic HCT at our institute between 2010 and 2024. The median age at the time of HCT was 43.5 years (range, 28-53 years). The median proportion of blasts in the bone marrow at HCT was 47.5% (range, 0.7-75.0%). The median duration from diagnosis to HCT was 65.5 days (range, 41-123 days). A total of five patients received single-unit cord blood transplantation, and one received bone marrow transplantation from an HLA-matched sibling donor. All patients received a myeloablative conditioning regimen, including 12 Gy total body irradiation and granulocyte colony-stimulating factor (G-CSF) combined with high-dose cytarabine, as well as standard cyclosporine and methotrexate for graft-versus-host disease prophylaxis. With a median follow-up of 41 months for survivors, three patients experienced relapse at 18, 5, and 2 months, whereas the remaining three patients were alive and disease-free at 173, 110, and 30 months after HCT. Our data demonstrate that G-CSF-combined myeloablative conditioning following allogeneic HCT could lead to favorable long-term remission for adult AML with inv(3)/t(3;3) in non-remission at HCT.