The anti-cytomegalovirus (CMV) activity and safety of oral maribavir in CMVseropositive allogeneic stem-cell transplant recipients were evaluated in a randomized, double-blind, placebocontrolled, dose-ranging study. After engraftment, 111 patients were randomized to receive CMV prophylaxis with maribavir (100 mg twice daily, 400 mg once daily, or 400 mg twice daily) or placebo. Within the first 100 days after transplantation, the incidence of CMV infection based on CMV pp65 antigenemia was lower in each of the respective maribavir groups (15%, P ‫؍‬ .046; 19%, P ‫؍‬ .116; 15%, P ‫؍‬ .053) compared with placebo (39%). Similarly, the incidence of CMV infection based on plasma CMV DNA was lower in each of the respective maribavir groups (7%, P ‫؍‬ .001; 11%, P ‫؍‬ .007; 19%, P ‫؍‬ .038) compared with placebo (46%). Anti-CMV therapy was also used less often in patients receiving each respective dose of maribavir (15%, P ‫؍‬ .001; 30%, P ‫؍‬ .051; 15%, P ‫؍‬ .002) compared with placebo (57%). There were 3 cases of CMV disease in placebo patients but none in the maribavir patients. Adverse events, mostly taste disturbance, nausea, and vomiting, were more frequent with maribavir. Maribavir had no adverse effect on neutrophil or platelet counts. These results show that maribavir can reduce the incidence of CMV infection and, unlike ganciclovir, does not cause myelosuppression. This trial is registered at www. ClinicalTrials.gov as #NCT00223925.

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We report here the transplantation of extensively purified "mobilized" peripheral blood CD34Thy-1 hematopoietic stem cells from 22 patients with recurrent or metastatic breast cancer. Patients were mobilized with either high-dose granulocyte colony-stimulating factor (G-CSF) alone or cyclophosphamide plus G-CSE Median purity of the stem cell product at cryopreservation was 95.3% (range, 91.1%-98.3%), and viability was 98.6% (range, 96.5%-100%). After high-dose chemotherapy with carmustine, cisplatin, and cyclophosphamide, CD34+Thy-1 cells at a median dose of 11.3 x 10(5) per kilogram (range, 4.7-163 x 10(5) per kilogram) were infused. No infusion-related toxicity was observed. Neutrophil recovery was prompt, with median absolute neutrophil count >500/microL by day 10 (range, 8-15 days) and >1000/microL by day 11 (range, 8-17 days). Median platelet recovery (>20,000/microL) was observed by day 14 (range, 9-42 days) and >50,000/microL by day 17 (range, 11-49 days). Tumor cell depletion below the limits of detection of a sensitive immunofluorescence-based assay was accomplished in all patients who had detectable tumor cells in apheresis products before processing. Although CD4+ T-cell reconstitution was slow, no unusual infections were observed. Neither early nor late graft failure was observed, and no patient required infusion of unmanipulated backup cells. At a median follow-up of approximately 1.4 years and a maximum follow-up of 2.5 years, 16 of the 22 patients remain alive, with 9 free of disease progression, and have stable blood counts. In summary, highly purified CD34+Thy-1+ cells used as the sole source of the hematopoietic graft result in rapid and sustained hematopoietic engraftment.

Dendritic cells (DCs) are powerful antigen-presenting cells. Because DCs are rare cells, methods to produce them in vitro are valuable ways to study their biologic properties and to generate cells for immunotherapy. This study defines the antigen-presenting properties of DCs generated in vitro from CD34+ cells of patients with breast cancer. The combination of cytokines flt3 ligand + c-kit ligand + granulocyte-macrophage colony-stimulating factor (GM-CSF) + interleukin-4 (IL-4) + tumor necrosis factor-alpha (TNF-alpha) was used to maximize the output of mature DCs in the culture of CD34+ cells while minimizing the production of monocytes. Cells grew and differentiated into DCs as measured by a time-dependent upregulation of cell surface antigens major histocompatibility complex class II, CD1a, CD80, CD86, CD40, and CD4, so that 40% +/- 9% (n = 6) of cells in culture at day 15 were CD1a+CD14-. Markers were acquired in the same sequence as on monocytes induced to differentiate with GM-CSF + IL-4. Differentiation was marked by a time-dependent increase in allostimulatory function, which, at its peak, was more potent than in cultures of DCs generated from monocytes with GM-CSF + IL-4, but was comparable on a cell-to-cell basis to that of mature monocytes cultured in flt3-ligand + c-kit-ligand + GM-CSF + IL-4 + TNF-alpha. Both CD34+ cell-derived and monocyte-derived DCs were able to process and to present tetanus toxoid and keyhole limpet hemocyanin to autologous T cells and to present major histocompatibility class I-binding peptides to CD8+ cytotoxic T lymphocytes inducing interferon-gamma production. Altogether, these results suggest that DCs generated from CD34+ cells of patients with breast cancer with flt3 ligand, c-kit ligand, GM-CSF, IL-4, and TNF-alpha are competent antigen-presenting cells, particularly for CD8+ cytotoxic T lymphocytes, and resemble mature monocyte-derived DCs in the assays described here.

A randomized clinical trial comparing tacrolimus with cyclosporine, both with short-course methotrexate, as prophylaxis against graft-vs.-host disease (GVHD) in allogeneic HLA-matched sibling bone marrow transplant patients was conducted. Cyclosporine was dosed to achieve a target concentration range between 150 and 450 ng/mL during the first 8 weeks after transplant. For tacrolimus, the target concentration range was 10-30 ng/mL during the first 8 weeks after transplant. A gradual tapering schedule of 20% per month during months 3-6 was then conducted for patients in both treatment arms. The efficacy of the immunosuppressive regimen was determined by the rate of acute GVHD grades II-IV The toxicity of the immunosuppressive regimen was determined by the occurrence of the creatinine exceeding 2 mg/dL, the creatinine doubling the baseline value, or the necessity for hemodialysis. Correlations between blood concentrations and efficacy and toxicity parameters were assessed. For both tacrolimus and cyclosporine, increasing blood concentrations were associated with greater renal dysfunction. For cyclosporine, there was a nonsignificant trend to an increased incidence of grades II-IV acute GVHD with lower cyclosporine blood concentrations (<300 ng/mL). In contrast, there did not appear to be a relationship between the blood concentrations of tacrolimus and the occurrence of acute GVHD. This suggests that optimization of efficacy while minimizing the risk for nephrotoxicity could be achieved by dosing tacrolimus to a targeted range between 10 and 20 ng/mL.