Etoposide + cytarabine plus granulocyte colony-stimulating factor mitigates daratumumab-associated impairment on stem cell mobilization in newly diagnosed multiple myeloma.

BACKGROUND AIMS: Daratumumab (dara) and lenalidomide (lena) have been reported to be associated with impaired stem cell mobilization.

METHODS

In this study, we evaluated the mobilization efficiency of etoposide + cytarabine (EA) plus granulocyte colony-stimulating factor (G-CSF) regimen in patients with newly diagnosed multiple myeloma (MM) receiving dara-lena based (n = 38) or lena-based induction therapy (n = 68).

RESULTS

The median total CD34+ cells collection was 18.89 × 10⁶/kg in the dara-lena group and 25.59 × 10⁶/kg in the lena group. All patients were successfully mobilized and most patients (≥94%) harvested ≥5 × 10⁶ CD34+ cells/kg in the two cohorts. In the dara-lena group, 89.5% of patients achieved at least 10 × 10⁶ CD34+ cells/kg, the optimal threshold for tandem transplantation, compared with 92.6% in the lena group. Patients receiving more than eight doses of dara showed a reduced CD34+ cell collection. The median time to neutrophil recovery post-autologous stem cell transplantation (ASCT) was delayed in the dara-lena group compared with the lena group (12 versus 11 days, P = 0.007), whereas a similar trend was observed for platelet recovery.

CONCLUSIONS

EA plus G-CSF was highly effective in achieving optimal CD34+ cell yields in patients treated with MM who were treated with dara-based induction regimens and may be preferred for those planned for tandem ASCT or at high risk of mobilization failure.