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The combination of lenalidomide (Revlimid ® , R) and dexamethasone (d) is a standard regimen for patients with relapsed/refractory multiple myeloma (rrMM). With this regimen, only a small fraction of patients will achieve high quality responses [≥ very good partial response (VGPR)]. The combination of bendamustine (B), lenalidomide and dexamethasone (BRd) has shown high efficacy in patients with advanced rrMM. However, dose-limiting haematotoxicity restricted its use in extensively pre-treated patient populations. This prospective, multicentre Phase II study evaluated the efficacy and safety of BRd in rrMM patients with one prior line of therapy. Fifty patients were enrolled (median age 68·5 years [range 46-83]) and were treated with B 75 mg/m 2  days 1, 2; R 25 mg days 1-21 and d (40/20 mg) days 1, 8, 15 and 22, for 6 28-day induction cycles, followed by 12 cycles with Rd alone. Pegfilgrastim was administered according to protocol-defined criteria. The study aimed to demonstrate a complete response (CR)/VGPR rate of >40% after induction therapy. Of 45 evaluable patients, 23 (51%) achieved a CR/VGPR. Grade 4 neutropenia or thrombocytopenia occurred in 17 (34%) and 8 (16%) of patients, respectively. BRd is a safe and efficacious regimen as a second line treatment for rrMM, leading to high quality responses in a considerable proportion of patients., (© 2016 John Wiley & Sons Ltd.)

The chemokine stromal cell-derived factor-1 (SDF-1) that is released by bone marrow (BM) stromal cells and contributes to stem cell homing may also play a role in the trafficking of leukaemic cells. We analysed SDF-1-induced intracellular calcium fluxes in leukaemic blasts from the peripheral blood of patients with newly diagnosed acute myeloid leukaemia (AML) and lymphoblastic leukaemia (B-lineage ALL), determined the effect of BM stromal cell-conditioned medium on in vitro transendothelial migration (TM) and measured expression of the SDF-1 receptor, CXCR4, by flow cytometry. AML FAB M1/2 blasts did not show calcium fluxes and TM was not stimulated. In myelomonocytic AML (M4/5), however, SDF-1 induced significant calcium fluxes and TM was increased twofold by the conditioned medium. M3 and M4 blasts with eosinophilia (M4eo) showed intermediate activity and M6 blasts showed no functional activity. In ALL, strong calcium fluxes and increased TM (2.5-fold) were observed. Accordingly, expression of CXCR4 was low in undifferentiated (M0) AML, myeloid (M1/2) AML and erythroid (M6) AML, but high [mean fluorescence (MF) > 50] in promyelocytic (M3) AML, myelomonocytic (M4/5) AML and B-lineage ALL. We conclude that, in AML, SDF-1 is preferentially active in myelomonocytic blasts as a result of differentiation-related expression of CXCR4. Functional activity of SDF-1 and high expression of CXCR4 in B-lineage ALL is in accordance with the previously described activity of SDF-1 in early B cells. SDF-1 may contribute to leukaemic marrow infiltration, as suggested by increased CXCR4 expression and migratory response in BM-derived blasts compared with circulating cells.

We report on the chemotherapy plus granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood progenitor cells (PBPCs) and their impact on haematopoietic recovery following high-dose chemotherapy. Twenty-four patients with advanced solid tumours or lymphomas received standard-dose chemotherapy with VP16, ifosfamide and cisplatin (VIP) followed by filgrastim (G-CSF; 5 micrograms/kg s.c. daily for 14 d) for the prevention of chemotherapy induced neutropenia and for the simultaneous mobilization of PBPCs. Maximal numbers of progenitors of different lineages were reached at day 11 (range 9-14) after VIP chemotherapy. A median of 0.415 x 10(9)/l CD34+ cells (range 0.11-1.98), 9000 CFU-GM/ml (range 2800-17,700), 3500 BFU-E/ml (range 400-10,800) and 200 CFU-GEMM/ml (range 0-4400) were recruited. One single apheresis yielded a median of 1.6 x 10(8) mononuclear cells/kg (range 0.2-5.4) or 5.4 x 10(6) CD34+ cells/kg body weight (range 0.2-24.2). Fourteen patients who showed at least a partial remission after two cycles of the standard-dose chemotherapy regimen were subjected to high-dose VIP chemotherapy (cumulative doses of 1500 mg/m2 VP16, 12 g/m2 ifosfamide and 150 mg/m2 cisplatin) with or without PBPC support. The first six patients were treated with growth factors only (IL-3/GM-CSF) and did not receive PBPCs, whereas the following eight patients were supported with PBPCs in addition to IL-3 and GM-CSF. Neutrophil recovery as well as platelet recovery were significantly faster in patients receiving PBPCs with a median of 6.5 d below 0.1 x 10(9) neutrophils/l and 3 d below 20 x 10(9) platelets/l as compared to 10.5 d and 8 d in control patients receiving growth factors only. The accelerated platelet recovery in patients supported with PBPCs might be explained--in the absence of detectable colony-forming units megakaryocyte--by the presence of glycoprotein IIb/IIIa+, non-proliferating endomitotic megakaryocytic precursor cells within G-CSF mobilized PBPCs. Our data demonstrate that chemotherapy plus G-CSF mobilized PBPCs accelerate both neutrophil and platelet recovery after high-dose VIP chemotherapy in patients with solid tumours or lymphomas.