This study compares the efficacy, toxicity, hematopoietic recovery, and cost of stem-cell mobilization using intermediate-dose cyclophosphamide (IDCy) plus granulocyte colony-stimulating factor (G-CSF) compared with etoposide (VP-16) plus pegylated granulocyte colony-stimulating factor (PEG-rhG-CSF) in multiple myeloma (MM) patients. Two hundred forty-four consecutive patients undergoing mobilization with IDCy (3-3.5 g/m2) plus G-CSF (n = 155) were compared with patients receiving VP-16 plus PEG-rhG-CSF (n = 89), including oral etoposide (n = 65) and intravenous etoposide (n = 24). Compared with IDCy, VP-16 use was associated with significantly higher median peak peripheral blood CD34 + cell count (8.20 [range: 1.84-84] × 106/kg vs 4.58 [range: 0.1-27.9] × 106/kg, P = .000), and ideal CD34 + cell yield of more than 6 × 106/kg (56.8% vs 35.1%, P = .001), notably with a higher efficacy in oral VP-16 use compared with IDCy use (CD 34 + cell counts: median peak peripheral blood 5.87 vs 4.58 × 106/kg and ≥6 × 106/kg [48.4% vs 35.1%]). The median number of apheresis courses was reduced from two in the IDCy group to one in the VP-16 group (P = .000). IDCy use was associated with significantly more frequent episodes of neutropenia (70.2% vs 35.2%; P = .000), intravenous antibiotic use (13.2% vs 11.4%; P = .672), and hospitalization (P = .000). The recoveries of neutrophils and platelets after autologous stem-cell transplantation were significantly faster in the VP-16 group compared with the IDCy group (P = .000). Our data indicate robust stem-cell mobilization in MM patients with VP-16 delivered either orally or intravenously. When compared with intravenous VP-16, oral VP-16 mobilization was associated with significantly more convenient, lower average total costs, and especially decreased the risk of hospital visits and exposure.

Serum B-cell maturation antigen (sBCMA) levels can serve as a sensitive biomarker in multiple myeloma (MM). In the research setting, sBCMA levels can be accurately detected by enzyme-linked immunosorbent assay (ELISA), but the approach has not been approved for clinical us.