Selection of a mobilization regimen for multiple myeloma based on the response to induction therapy: Granulocyte-colony stimulating factor (G-CSF) alone versus high-dose cyclophosphamide plus G-CSF

To evaluate the feasibility of selecting a mobilization regimen based on the response to induction therapy, we retrospectively analyzed 179 multiple myeloma patients who underwent stem cell mobilization. In comparison with patients who achieved at least a very good partial response (VGPR) to induction therapy and received granulocyte-colony stimulating factor (G-CSF) alone and patients who did not achieve a VGPR and received cyclophosphamide (CY) + G-CSF, treatment-related toxicity was greater and neutrophil engraftment was slower in the CY than the G-CSF group. The rate of requisite mobilization (≥ 2.0 × 10⁶/kg) was similar in both groups. Overall and progression-free survival was not different between patients in the G-CSF group and patients who achieved at least VGPR and received CY + G-CSF. In conclusion, response-adapted selection of a mobilization regimen is appropriate. G-CSF alone should be the preferred treatment for patients who achieved at least a VGPR to induction therapy.