Higher efficacy of intermediate dose cytarabine + G‐CSF compared to cyclophosphamide + G‐CSF in hematopoietic stem cell mobilization in patients with multiple myeloma

Abstract

Background There are several regimens used in hematopoietic stem cell (HSC) mobilization in multiple myeloma (MM). Cyclophosphamide (Cy) is one of the most commonly used agents, although it does not always result in collecting adequate number of CD34+ cells. Recently, cytarabine (Ara‐C) has been proposed as potentially efficient and safe option. Aims Since the data regarding Ara‐C in HSC mobilization is limited, the aim of our study was to compare retrospectively the efficiency and toxicity of G‐CSF combined with either Ara‐C or Cy in MM patients. Materials & Methods Of a total of 89 patients, 43 received low or intermediate doses of Cy, and 46 were treated with 800 mg/m2/day of Ara‐C administered for two days. Results The mean peak of CD34+ cells/ul in peripheral blood was 132 (range, 84‐202) in Ara‐C and 51 (range, 29‐69) in Cy cohort (p < 0.001). The median number of collected CD34+ cells (×106/kg) was 10.3 (range, 4.2‐17.9) vs 4.5 (range, 2.7‐8.9), respectively (p < 0.001). Mobilization failure was observed in one patient in Ara‐C cohort (2%) and in 8 patients treated with Cy (19%) (p = 0.013). In the Ara‐C group 98% of patients obtained more than 4×106 CD34+ cells/kg required for tandem transplantation. Moreover, we observed a trend toward increased paraprotein levels measured at transplant compared to before HSC mobilization in Ara‐C cohort and significantly higher transfusion rates in that group. Conclusion Our findings confirm higher HSC mobilization efficacy of Ara‐C compared to Cy in MM patients. However, lower transfusions rate and better disease control of Cy may justify its use in some cases.

Etoposide combined with cytarabine and pegfilgrastim for poorly mobilizing patients with multiple myeloma and lymphoma: A prospective multicentre study

“…In addition, the incidence of grade 3–4 haematological adverse events was similar or lower to that reported for other chemo‐based mobilization treatments 11,20,21 . However, these cross‐trial comparisons should be interpreted with caution as 43.1% of our patients required platelet transfusions, with the rate of these transfusions being higher than those reported by other studies 11,22 . This finding can be explained by the poor mobilizers requiring more platelet transfusions and the combined use of etoposide and cytarabine 12 .…”

“…11,20,21 However, these cross-trial comparisons should be interpreted with caution as 43.1% of our patients required platelet transfusions, with the rate of these transfusions being higher than those reported by other studies. 11,22 This finding can be explained by the poor mobilizers requiring more platelet transfusions and the combined use of etoposide and cytarabine. 12 A possible strategy to reduce platelet transfusions would be to decrease the dose of cytarabine from 1.2 to 0.8 g/m 2 in the EAP regimen.…”