e13079 Background: High levels of VEGF protein correlate with a poor prognosis translating into poor OS of cancer patients. Bevacizumab in combination with paclitaxel significantly prolongs PFS and increases the objective RR in patients with breast cancer. Serum levels of VEGF increase, in a dose-dependent manner, with all oral TKIs inhibiting VEGFR-2; this reflects a potential escape mechanism of the tumor, consequently overcoming antiangiogenic TKI activity. Combination of sorafenib plus bevacizumab has impressive clinical activity in patients with mRCC, potentially due to overcoming such escape mechanisms. Methods: Titration of the minimal effective (MED) or maximum tolerable dose (MTD) of bevacizumab in combination with regular dosed weekly paclitaxel (90 mg/m2 d1,8,15 q4wks) and continuous oral sorafenib (200 mg bid), that is sufficient to suppress the increase of VEGF levels. A total of 3-6 pts have been or will be treated per dose level with 0 mg, 1 mg, 2 mg, 3 mg and 5 mg bevacizumab q2wks, respectively. Blood levels of VEGF are assessed at baseline, and 8 h post-dose of first sorafenib on days 1 and 15 before the initial dose of bevacizumab, and thereafter before every bevacizumab infusion. Results: Currently 12 pts with various solid tumors were enrolled with bevacizumab doses of 0 mg (n=4), 1 mg (n=6), and 2 mg (n=2). Drug-related adverse events (AEs) observed so far were predominantly hand-foot- syndrome (HFS) (6 pts; CTC 3: 3pts), rash (CTC3: 1pt), stomatitis (3 pts; CTC3: 1 pt), PNP (2 pts; CTC3: 1 pt), diarrhea (CTC 3: 2 pts), granulocytopenia (CTC4: 1 pt), hoarseness (2 pts; CTC3: 1 pt). Treatment-related AEs leading to dose reduction, interruption or discontinuation were HFS (2 pts) and PNP (1 pt). So far, toxicities were not related to the dose of bevacizumab. Currently 9 pts are evaluable for response according to RECIST (ongoing SD: 8 pts, PD: 1 pt). Preliminary VEGF-data support the biological activity of the treatment. Conclusions: The combination of paclitaxel with sorafenib and bevacizumab is potentially highly efficacious, but toxicities might require special precautions. MED or MTD of bevacizumab in this combination have not been reached yet. No significant financial relationships to disclose.

Sorafenib (BAY 43-9006), a multikinase inhibitor, has been shown to inhibit tumor growth and tumor angiogenesis by targeting Raf kinase, vascular endothelial growth factor receptor, and platelet-derived growth factor receptor. This study investigated the safety, pharmacokinetics, and preliminary efficacy of sorafenib in combination with gemcitabine and cisplatin.

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal disorder of haematopoietic stem cells associated with a somatic mutation in the phosphatidylinositol glycan complementation class A (PIG-A) gene. The only curative option is an allogeneic stem cell transplant (SCT), although treatment is hazardous. A 46-year-old male patient with PNH and obvious signs of severe, progressive haemolysis was transplanted in July 2002 with highly purified CD34 T-cell depleted peripheral blood stem cells from his HLA-identical brother. Prior to transplantation, the PNH was resistant to immunosuppressive therapy. The patient received 6.1 x 10(6)/kg bodyweight CD34-positive cells with a proportion of CD3-positive cells of 0.81 x 10(4)/kg bodyweight. After engraftment, 12 days post transplant (neutrophils > 1.0/nl) the patient's physical condition steadily improved and parameters of haemolysis decreased. No glycophosphatidylinositol deficient cells in peripheral blood could be detected by flow cytometry 40 and 100 days after transplant. We conclude that PNH may be cured by allogeneic CD34-enriched SCT from a sibling donor attempting to avoid acute GVHD and to reduce cumulative organ toxicity by using this transplantation modality.

The feasibility of transplantation using highly purified G-CSF-mobilized peripheral blood CD34+ cells from HLA-identical sibling donors without prophylactic post-transplant immunosuppression was prospectively studied in 10 adult first chronic phase chronic myeloid leukemia (CML) patients with special reference to graft engineering performance and follow-up studies of minimal residual disease and immune reconstitution. CD34+ cells were enriched by clinical-scale magnetic-activated cell separation (MACS) using iron-dextran beads bound to monoclonal anti-CD34 antibody. Grafts contained a median of 9.7 (range 1.7–16.6) × 106 CD34+ cells per kilogram of recipient body weight with a purity between 94.5% and 98.3% (median 97.2%). The median number of transfused CD3+ T lymphocytes was 1.0 (range 0.5–8.5) × 104/kg, corresponding to a log10 t lymphocyte depletion between 3.8 and 5.0 (median 4.6). all patients engrafted rapidly with a median duration to neutrophil counts >500/μl of 8 (range 8–19) days and to self-sustaining platelet counts >20 000/μl of 12 (range 9–25) days. Isolated skin acute graft-versus-host disease (GVHD) of stages I to II occurred in three patients. One patient developed secondary graft failure and was successfully salvaged by an unmanipulated blood stem cell graft from the same donor. All 10 patients are surviving in complete hematologic, cytogenetic and molecular remission (four patients after donor lymphocyte infusions) between 12 and 22 (median 16) months post transplant. In conclusion, transplantation of MACS-purified blood CD34+ cells from HLA-identical sibling donors in adult CML patients appears safe, effectively prevents acute GVHD without prophylactic post-transplant immunosuppression, and is capable of inducing complete cytogenetic and molecular remissions. Bone Marrow Transplantation (2000) 26, 823–829.

The immunosuppressant rapamycin is known to be a potent inhibitor of cytokine driven proliferation of T-lymphocytes and other cell types. Here we have examined the effect of rapamycin on the myeloblastic cell line M1 which responds to interleukin-6 (IL-6) with growth arrest and monocytoid differentiation. Single-agent rapamycin led to a retardation of M1 cell growth. In spite of this intrinsic antiproliferative effect, rapamycin was found to abrogate IL-6 induced growth arrest. Concomitant exposure to rapamycin and IL-6 also reduced the extent of monocytoid differentiation as compared to treatment with IL-6 alone. Excess levels of the FK-506 analogue ascomycin reversed the antagonistic effect of rapamycin on IL-6 mediated growth suppression, suggesting that this biological action of rapamycin is mediated by a rapamycin/immunophilin complex. The findings demonstrate that rapamycin can also act as an antagonist of cytokine induced growth arrest and differentiation.

During long-term interferon alpha-2b (IFN) therapy of Philadelphia chromosome-positive chronic myelogenous leukemia (CML) patients, short-term effects of tumor necrosis factor alpha (TNF) on peripheral leukocyte counts, as well as cortisol and corticotropin (ACTH) release were studied. TNF (40-160 micrograms/m2) was given as a 2-h infusion on 5 consecutive days every 3 weeks, in addition to s.c. daily IFN injections (4 mio U/m2), to four (two male/two female) patients, who had been treated for more than 8 months with IFN and additionally for 0-7 months with TNF. Leukocyte counts, cortisol, and ACTH were determined at 30-min intervals between 4 p.m. and midnight. Profiles were determined the day before and on day 1 of TNF therapy. Leukocyte numbers decreased 30 min after start of TNF administration and increased 30-60 min later with a rebound until the next TNF application. The increase of leukocyte counts was due mostly to neutrophil granulocytes. ACTH levels increased 30 min, cortisol 60 min, and leukocyte counts 90 min after start of TNF infusion. Metopirone, an inhibitor of cortisol synthesis given to one patient, suppressed the TNF-induced stimulation of cortisol secretion and subsequent increase of leukocyte counts, while ACTH blood levels were enhanced. It was concluded that leukocyte count increases after TNF/IFN administration might be related to TNF-evoked cortisol secretion.

Activity of the interferon-induced enzyme 2'-5' oligoadenylate synthetase (2-5 OAS) was measured in peripheral blood mononuclear cells (PBMCs) and serum of patients with chronic phase Ph'-positive chronic myelogenous leukemia (CML) treated with interferon-alpha (IFN-alpha) (4 x 10(6) IU/m2) alone or in combination with 50 micrograms IFN-gamma. At the beginning of IFN therapy, marked elevation of 2-5 OAS titers was detected in PBMCs (pretreatment 0.03-1.62, median 0.2; during treatment 0.8-13.14, median 4.31; 22 patients studied) and in serum (pretreatment 21-156 pmol/dl, median 62; during treatment 532-1740 pmol/dl, median 800; eight patients studied). However, 2-5 OAS titers were not related to clinical outcome or IFN therapy and also during IFN resistance elevated 2-5 OAS activity in PBMCs (median 3.45; range 1.05-13.14; 11 patients studied) were detected. These data argue against direct involvement of the 2-5 OAS system in the therapeutic effect of IFN in CML. However, 2-5 OAS titers in PBMCs or serum appear to be a reliable control of biologically active IFN therapy.

Three variants of the human monoblastic cell line U937 with different degrees of sensitivity to the antiproliferative action of interferon-alpha (IFN-alpha were examined for phenotypic differences. The highly IFN-sensitive variant U937-V expressed twice as many IFN-alpha binding sites as both its IFN-alpha-resistant derivative U937-VR and the cell line U937 exhibiting a 20-fold reduction in IFN-alpha sensitivity as compared to U937-V cells. All three variants were IFN-reactive with regard to induction of 2',5'-oligoadenylate (2-5A) synthetase activity and were similarly sensitive to the growth-inhibiting action of IFN-gamma and tumor necrosis factor. Responsiveness to the antiproliferative effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), however, was confined to cell lines U937 and U937-VR. Although expressing a comparable number of GM-CSF receptors, the highly IFN-sensitive variant U937-V was refractory to GM-CSF. Flow cytometry revealed a marked difference in the expression of the antigen CD11b which was detectable on 85% of cells of the U937-V line but only on approximately 25% of cells derived from the U937 and U937-VR lines. Results thus demonstrate opposite sensitivity of U937 cells to the growth-inhibiting action of IFN-alpha and GM-CSF, apparently dependent on the state of U937 differentiation as determined by expression of the CD11b antigen.

Interferons (IFNs) were first described in 1957 [35]. During the last two decades, these cytokines have received increasing attention in the treatment of cancer, particularly since in 1981 highly purified material produced by recombinant DNA technology has become available in addition to natural IFNs [25, 51, 59]. So far, the most impressive clinical results have been achieved in hematologic disorders, especially in hairy cell leukemia [26, 41, 54].