Clofarabine/cyclophosphamide for debulking before stem cell transplantation

Area of Science:

• Hematology
• Oncology
• Stem Cell Transplantation

Background:

• Allogeneic haematopoietic stem cell transplantation (HSCT) offers curative potential for chemotherapy-refractory acute leukaemia.
• Effective disease control before HSCT is critical for achieving long-term survival post-transplant.

Purpose of the Study:

• To evaluate the efficacy and safety of clofarabine/cyclophosphamide (ClofCy) as a debulking regimen prior to HSCT in patients with refractory acute leukaemia.

Main Methods:

• Retrospective analysis of 20 patients (16 AML, 4 ALL) aged 21-64 years with refractory leukaemia.
• Patients received debulking therapy with clofarabine (10 mg/m², days 1-4) and cyclophosphamide (200 mg/m², days 1-4).
• HSCT was performed in 15 patients using myeloablative or dose-reduced conditioning.

Main Results:

• ClofCy (1-4 cycles) was well-tolerated and achieved substantial leukaemic cell reduction in all patients.
• All 15 patients who underwent HSCT achieved engraftment, full donor chimerism, and complete haematologic remission.
• Median survival post-HSCT was 531 days, with 6 patients alive at a median of 1245 days; 7 patients relapsed, and 2 died from non-relapse causes.

Conclusions:

• Clofarabine/cyclophosphamide represents a novel and effective debulking strategy for chemotherapy-refractory acute leukaemia prior to HSCT.
• Further clinical studies are needed to confirm if this protocol improves long-term outcomes in refractory leukaemias.