No abstract

Troglitazone is not an active agent for the treatment of metastatic colorectal cancer.

Through an immune-mediated graft-versus-leukemia effect, allogeneic hematopoietic stem cell transplantation (HSCT) affords durable clinical benefits for many patients with hematologic malignancies. Nonetheless, subjects with high-risk acute myeloid leukemia or advanced myelodysplasia often relapse, underscoring the need to intensify tumor immunity within this cohort. In preclinical models, allogeneic HSCT followed by vaccination with irradiated tumor cells engineered to secrete GM-CSF generates a potent antitumor effect without exacerbating the toxicities of graft-versus-host disease (GVHD). To test whether this strategy might be similarly active in humans, we conducted a Phase I clinical trial in which high-risk acute myeloid leukemia or myelodysplasia patients were immunized with irradiated, autologous, GM-CSFsecreting tumor cells early after allogeneic, nonmyeloablative HSCT. Despite the administration of a calcineurin inhibitor as prophylaxis against GVHD, vaccination elicited local and systemic reactions that were qualitatively similar to those previously observed in nontransplanted, immunized solid-tumor patients. While the frequencies of acute and chronic GVHD were not increased, 9 of 10 subjects who completed vaccination achieved durable complete remissions, with a median follow-up of 26 months (range 12-43 months). Six long-term responders showed marked decreases in the levels of soluble NKG2D ligands, and 3 demonstrated normalization of cytotoxic lymphocyte NKG2D expression as a function of treatment. Together, these results establish the safety and immunogenicity of irradiated, autologous, GM-CSF-secreting leukemia cell vaccines early after allogeneic HSCT, and raise the possibility that this combinatorial immunotherapy might potentiate graft-versus-leukemia in patients.bone marrow transplant ͉ GVL ͉ MICA ͉ NKG2D ͉ tumor immunity

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The oncogenic transcription factor signal transducer and activator of transcription 3 (STAT3) is frequently activated inappropriately in a wide range of hematological and solid cancers, but clinically available therapies targeting STAT3 are lacking. Using a computational strategy to identify compounds opposing the gene expression signature of STAT3, we discovered atovaquone (Mepron), an antimicrobial approved by the US Food and Drug Administration, to be a potent STAT3 inhibitor. We show that, at drug concentrations routinely achieved clinically in human plasma, atovaquone inhibits STAT3 phosphorylation, the expression of STAT3 target genes, and the viability of STAT3-dependent hematological cancer cells. These effects were also observed with atovaquone treatment of primary blasts isolated from patients with acute myelogenous leukemia or acute lymphocytic leukemia. Atovaquone is not a kinase inhibitor but instead rapidly and specifically downregulates cell-surface expression of glycoprotein 130, which is required for STAT3 activation in multiple contexts. The administration of oral atovaquone to mice inhibited tumor growth and prolonged survival in a murine model of multiple myeloma. Finally, in patients with acute myelogenous leukemia treated with hematopoietic stem cell transplantation, extended use of atovaquone for prophylaxis was associated with improved relapse-free survival. These findings establish atovaquone as a novel, clinically accessible STAT3 inhibitor with evidence of anticancer efficacy in both animal models and humans.

CD4+CD25+FOXP3+ regulatory T cells (Treg) successfully control graft-versus-host-disease (GVHD) in animal models. In humans, incomplete reconstitution of Treg after allogeneic hematopoietic stem cell transplantation (HSCT) has been associated with chronic GVHD. Recent studies have demonstrated that IL-2 infusions expand Treg in vivo. However, the effectiveness of this therapy depends on the number of cells capable of responding to IL-2. We examined the effect of low-dose IL-2 infusions on Treg populations after HSCT in patients who also received infusions of donor CD4+ lymphocytes. Utilizing FOXP3 as a Treg marker, we found that patients who received CD4+DLI concomitantly with IL-2 had greater expansion of Treg compared to patients who received IL-2 (p=0.03) or CD4+DLI alone (p=0.001). FOXP3 expression correlated with absolute CD4+CD25+ cell counts. Moreover, expanded CD4+CD25+ T cells displayed normal suppressive function and treatment with CD4+DLI and IL-2 was not associated with GVHD. This study suggests that administration of low-dose IL-2 combined with adoptive CD4+ cellular therapy may provide a mechanism to expand Treg in vivo.

OBJECTIVE -Early pregnancy losses increase with marked hyperglycemia in diabetic pregnancy. However, mean loss rates do not differ from those of nondiabetic pregnancy. This observation might be explained by increased fetal losses at the extremes of glycemia in diabetic and nondiabetic pregnancy. To test this hypothesis, we examined relationships of proximate measures of prior glycemia, glycated protein and fructosamine, to pregnancy loss. RESEARCH DESIGN AND METHODS-A total of 389 diabetic and 429 nondiabetic pregnant subjects participated in the Diabetes In Early Pregnancy study. Glycated protein and fructosamine measurements were standardized as multiples of control values for each center (Z score). The logarithm of odds of pregnancy loss were plotted against Z scores and tested by logistic models.RESULTS -Mean pregnancy loss rates were 12% in diabetic and 13% in normal pregnancies. However, over six intervals of glycated protein in diabetic pregnancy, fetal loss rates at the upper and lower extremes (24 and 33%, respectively) were approximately threefold higher than the four intervening rates (8 -14%). The odds ratio of pregnancy loss for these extreme intervals to the intervening intervals is 3.0 (P ϭ 0.01). Nondiabetic losses showed a similar pattern. In confirmation, logit pregnancy losses were increased in a J-shaped curve at the glycemic extremes in normal (P Ͻ 0.019) and diabetic (P Ͻ 0.015) pregnancy. The upper glycemic extreme in diabetic pregnancy was two-to fivefold higher than in control pregnancy.CONCLUSIONS -Pregnancy losses are increased at the extremes of glycemia in both normal and diabetic pregnancy but at higher levels in diabetic pregnancy. The data suggest defensive adaptations against hyperglycemia in diabetic pregnancy.

BACKGROUND There is no effective systemic therapy for patients with hepatocellular carcinoma. A recent trial reported a moderate antitumor activity for gemcitabine among Asian patients with advanced hepatocellular carcinoma. This led to our examination of the efficacy and tolerability of the drug in a population of U.S. patients. METHODS Thirty patients with measurable, unresectable, or metastatic hepatocellular carcinoma who had received at least one previous form of systemic therapy were enrolled. All patients were required to have adequate major organ function and performance status. Patients received gemcitabine (1000 mg/m2 intravenously over 30 minutes weekly) for 3 consecutive weeks followed by a 1‐week rest. Patients were assessed radiographically every 8 weeks. RESULTS All 30 patients were evaluable for response and toxicity. Ninety cycles of therapy were administered (median 2, range 1–8). No complete or partial responses were observed. Nine patients (30%) had stable disease (median duration 7.4 months, range 2–17). Median survival for all 30 patients was 6.9 months (95% confidence interval, 4.5–13.5) and the 1‐year survival rate was 40%. Mild hematologic toxicity occurred. Two patients (7%) developed Grade 4 neutropenia and one patient (3%) experienced Grade 3 thrombocytopenia. There were no episodes of febrile neutropenia. One patient who had previously undergone orthotopic liver transplantation developed hemolytic‐uremic syndrome that resolved with discontinuation of chemotherapy and plasmapheresis. CONCLUSIONS Although generally well tolerated, gemcitabine had minimal effect in patients with advanced hepatocellular carcinoma. Cancer 2002;94:3186–91. © 2002 American Cancer Society. DOI 10.1002/cncr.10607