Remobilization of hematopoietic stem cells with high‐dose methotrexate and cytarabine in patients with non‐ H odgkin's lymphoma and multiple myeloma after failure to mobilize with chemotherapy and cytokines

Background High‐dose chemotherapy supported by autologous stem cell transplantation is an effective treatment for patients with relapsed or refractory non‐Hodgkin's lymphomas ( NHLs ) and fit patients with multiple myeloma ( MM ). However, failure rates of hematopoietic stem cell mobilization are estimated to be between 5 and 30%, respectively. Thus, we investigated the efficacy of the combination chemotherapy of high‐dose methotrexate (MTX) and cytarabine with granulocyte‐colony‐stimulating factor (G‐CSF) as a remobilization method in those who failed a prior mobilization and collection with chemotherapy and G ‐ CSF . Study Design and Methods Mobilization failure was defined as a collection of fewer than 5 × 10 6 CD 34+ cells after three to five apheresis procedures. MTX (3500 mg/m 2 in a 120‐min infusion) on D ay 1 and cytarabine (3000 mg/m 2 infusion for 120 min) on D ay 4 and D ay 5 were followed by G ‐ CSF (10 μg/kg daily). Results A total of eight patients (six NHL and two MM ; median age, 55 years) who had failed in prior mobilization with conventional chemotherapy and G ‐ CSF underwent the second mobilization as described in the method. Successful collection of CD 34+ cells (> 5 × 10 6 /kg) was achieved in six patients (75%) with three to five apheresis procedures. The total yield of CD 34+ cells/kg body weight was 6.28 × 10 6 /kg (median; range, 1.53 × 10 6 ‐10.09 × 10 6 /kg). Conclusions This preliminary result warrants further investigation of high‐dose MTX and cytarabine plus G ‐ CSF as a means to remobilize stem cells in those with prior failure to mobilize stem cells with chemotherapy and G ‐ CSF .