High activity of sorafenib in FLT3-ITD-positive acute myeloid leukemia synergizes with allo-immune effects to induce sustained responses.

Preliminary evidence suggests that the multikinase inhibitor sorafenib has clinical activity in FLT3-ITD-positive (FLT3-ITD) acute myeloid leukemia (AML). However, the quality and sustainability of achievable remissions and clinical variables that influence the outcome of sorafenib monotherapy are largely undefined. To address these questions, we evaluated sorafenib monotherapy in 65 FLT3-ITD AML patients treated at 23 centers. All but two patients had relapsed or were chemotherapy-refractory after a median of three prior chemotherapy cycles. Twenty-nine patients (45%) had undergone prior allogeneic stem cell transplantation (allo-SCT). The documented best responses were: hematological remission in 24 patients (37%), bone marrow remission in 5 patients (8%), complete remission (with and without normalization of peripheral blood counts) in 15 patients (23%) and molecular remission with undetectable FLT3-ITD mRNA in 10 patients (15%), respectively. Seventeen of the patients without prior allo-SCT (47%) developed sorafenib resistance after a median treatment duration of 136 days (range, 56-270 days). In contrast, allo-SCT patients developed sorafenib resistance less frequently (38%) and significantly later (197 days, range 38-225 days; P=0.03). Sustained remissions were seen exclusively in the allo-SCT cohort. Thus, sorafenib monotherapy has significant activity in FLT3-ITD AML and may synergize with allogeneic immune effects to induce durable remissions.

Randomised phase II trial of gemcitabine plus vinorelbine vs gemcitabine plus cisplatin vs gemcitabine plus capecitabine in patients with pretreated metastatic breast cancer.

BACKGROUND: An increasing proportion of patients are exposed to anthracyclines and/or taxanes in the adjuvant or neoadjuvant setting. Re-exposure in the metastatic stage is limited by drug resistance, thus evaluation of non-cross-resistant regimens is mandatory. METHODS: Anthracycline-pretreated patients were randomly assigned to three gemcitabine-based regimens. Chemotherapy consisted of gemcitabine 1.000 mg m(-2) plus vinorelbin 25 mg m(-2) on days 1+8 (GemVin), or plus cisplatin 30 mg m(-2) on days 1+8 (GemCis), or plus capecitabine 650 mg m(-2) b.i.d. orally days 1-14 (GemCap), q3w. The primary end point was response rate. RESULTS: A total of 141 patients were recruited on the trial. The overall response rates were 39.0% (GemVin), 47.7% (GemCis) and 34.7% (GemCap). Median progression-free survival was estimated with 5.7, 6.9 and 8.3 months, respectively. Corresponding median survival times were 17.5 (GemVin), 13.0 (GemCis) and 19.4 months (GemCap). Neutropenia ≥grade 3 occurred in 16.7% (Gem/Vin), 4.4% (GemCis) and 0% (Gem/Cap), whereas non-haematological toxicities were rarely severe except grade 3 hand-foot syndrome in 2.0% of the GemCap patients (per patient analysis). CONCLUSIONS: This randomised phase II trial has revealed comparable results for three gemcitabine-based regimens regarding treatment efficacy and toxicity. Gemcitabine-based chemotherapy appears to be a worthwhile treatment option for pretreated patients with metastatic breast cancer.

Positively selected autologous blood CD34+ cells and unseparated peripheral blood progenitor cells mediate identical hematopoietic engraftment after high-dose VP16, ifosfamide, carboplatin, and epirubicin.

To investigate the feasibility of peripheral blood CD34+ cell selection and to analyze CD34+ cell-mediated engraftment after high-dose chemotherapy, we performed a phase I/II trial in 21 patients with advanced malignancies. The rationale for the selection of CD34+ cells from peripheral blood progenitor cell (PBPC) collections is based on the observation that contaminating tumor cells can be depleted approximately 3 logs using this procedure. CD34+ cells from chemotherapy+granulocyte colony-stimulating factor-mobilized PBPCs were positively selected with an avidin-biotin immunoadsorption column (CEPRATE SC system). One leukapheresis product with a median number of 2.8 x 10(6) CD34+ cells/kg was labeled with a biotinylated anti-CD34 monoclonal antibody and subsequently processed over the column. The yield of selected CD34+ cells was 73% +/- 24.6%. The purity of the CD34+ cell fraction was 61.4% +/- 19.7%. CD34+ cells were shown to represent predominantly committed progenitors coexpressing CD33, CD38, and HLA-DR molecules (lin+). They gave rise to myeloid as well as erythroid and multilineage colonies in vitro. In addition, positively selected CD34+ cells also comprised early hematopoietic progenitor cells, as shown by the presence of CD34+/lin- cells. Transfusion of positively selected CD34+ cells (2.5 x 10(6) CD34+/kg; range, 0.45 to 5.1) after high-dose VP16 (1,500 mg/m2), ifosfamide (12 g/m2), carboplatin (750 mg/m2), and epirubicin (150 mg/m2) (VIC-E) in 15 patients resulted in a rapid and stable engraftment of hematopoiesis without any adverse events. As compared with 13 historical control patients reconstituted with a comparable number of unseparated PBPCs, time to neutrophil and platelet recovery was identical in both groups (absolute neutrophil count > 500/microL, day + 12; platelet count > 50,000/microL, day + 15). These data indicate that autologous peripheral blood CD34+ cells and unseparated PBPCs mediate identical reconstitution of hematopoiesis after high-dose VIC-E chemotherapy. Because positive selection of CD34+ cells from mobilized blood results in a median 403-fold depletion of T cells, allogeneic CD34+ cells from mobilized blood should be investigated as an alternative to bone marrow cells for allotransplantation.

Peripheral blood progenitor cells mobilized by chemotherapy plus granulocyte-colony stimulating factor accelerate both neutrophil and platelet recovery after high-dose VP16, ifosfamide and cisplatin.

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.

Haematopoietic growth factors and peripheral blood stem cells as supportive agents in dose intensification.

We have studied the requirements that have to be met to combine effective cancer chemotherapy with the mobilisation of peripheral blood stem cells (PBSC). We have shown that there is a differential induction of high numbers of PBSC following standard-dose chemotherapy (VIP) plus treatment with colony-stimulating factors. The combined sequential administration of interleukin 3 (IL-3) plus granulocyte-macrophage colony-stimulating factor (GM-CSF) induced maximal numbers of PBSC, including colony-forming unit-granulocyte, erythrocyte, monocyte/macrophage, megakaryocyte (CFU-GEMM) and colony-forming unit-megakaryocyte (CFU-Meg), compared with the application of GM-CSF, granulocyte colony-stimulating factor (G-CSF) or chemotherapy alone. The number of CD34+ cells was highly variable depending on the prior treatment given to the patients. Mobilised CD34+ cells--depending on the cytokines used for recruitment--had a varying cloning efficiency, and were heterogeneous as to their level of commitment. Retransfusion of G-CSF-primed progenitor cells to pilot patients following high-dose chemotherapy demonstrated that PBSC recruited by standard-dose chemotherapy plus G-CSF accelerated both neutrophil and platelet recovery.