Final Results of a Phase I/II Trial of the Combination Bendamustine and Rituximab With Temsirolimus (BeRT) in Relapsed Mantle Cell Lymphoma and Follicular Lymphoma.

In this phase I/II study, we explored the combination of Temsirolimus with Bendamustine and Rituximab (BeRT) in patients with relapsed or refractory (r/r) follicular lymphoma (FL) or mantle cell lymphoma (MCL). Patients with 1 to 3 previous therapies received Bendamustine (90 mg/m2, day 1 + 2) and Rituximab (375 mg/m2, day 1) with Temsirolimus in doses from 25 to 75 mg in phase I and 50 mg Temsirolimus in phase II, added on day 1, 8, 15 of a 28 days cycle. The primary endpoint of the phase II was ORR at the end of treatment. Overall, 39 (29 MCL, 10 FL) patients were included. Median age was 71 years and median pretreatment number was 2. Grade 3/4 non-hematologic adverse events were rare and included hyperglycemia in 3 patients (7%) and angioedema in 2 patients (5%). Infectious complications grade 3/4 were observed in 9 patients (23%). Hematologic grade 3/4 events included leukopenia in 22 (56%), neutropenia in 18 (46%), lymphopenia in 16 (41%) and thrombocytopenia in 14 patients (36%). An objective response (best response) was observed in 33/39 patients (89%; 24 MCL (89%) and 9 FL (90%)), including 14 CR (38%; 12 MCL (36%) and 2 FL (20%)). Median PFS is 1.5y for MCL and 1.82 years for FL, and median OS has not been reached for either entity. This data demonstrates promising efficacy of Temsirolimus in r/r MCL and FL with acceptable toxicity. The BeRT regimen may be used as a treatment option for both entities.

The targeted immunocytokine L19-IL2 efficiently inhibits the growth of orthotopic pancreatic cancer.

PURPOSE: Effective control of pancreatic cancer has been hampered primarily by the lack of tumor specificity of current treatment modalities. The highly specific antibody-mediated delivery of therapeutic agents to the tumor microenvironment might overcome this problem. We therefore investigated the therapeutic efficacy of the targeted immunocytokine L19-Interleukin-2 (L19-IL2), consisting of the human single-chain Fv antibody L19, which is highly specific for the extradomain B (ED-B) of fibronectin, and the human cytokine IL-2, in pancreatic cancer. EXPERIMENTAL DESIGN: Therapeutic effects of L19-IL-2, IL-2, and gemcitabine on tumor growth and metastasis were evaluated in orthotopic mouse models for pancreatic cancer. Immunohistochemistry was done to define ED-B expression, tumor necrosis, apoptosis, proliferation, and invasion of macrophages and natural killer (NK) cells. NK cells were depleted by i.v. injection of an anti-asialo-GM-1 antibody. RESULTS: ED-B is selectively expressed in human pancreatic cancer and in primary tumors and metastases of the mouse models. L19-IL-2 therapy was clearly superior to untargeted IL-2 or gemcitabine and inhibited tumor growth and metastasis with remarkable long-term tumor control. Therapeutic effects were associated with the induction of extensive tumor necrosis and inhibition of tumor cell proliferation. Immunohistochemistry revealed an increase of macrophages and NK cells in the tumor tissue, suggesting immune-mediated mechanisms. The functional relevance of NK cells for the therapeutic effect of the targeted immunocytokine L19-IL-2 was confirmed by NK cell depletion, which completely abolished its antitumor efficacy. CONCLUSIONS: These preclinical results strongly encourage the initiation of clinical studies using L19-IL-2 in pancreatic cancer.

Activin A stimulates vascular endothelial growth factor gene transcription in human hepatocellular carcinoma cells.

BACKGROUND & AIMS: Up-regulation of vascular endothelial growth factor is known to play a critical role in hepatocellular tumor biology. In an attempt to identify factors responsible for vascular endothelial growth factor induction in human hepatocellular carcinoma, we evaluated the effects of activin A, a member of the transforming growth factor-beta cytokine superfamily, on vascular endothelial growth factor gene expression. METHODS: Expression of vascular endothelial growth factor, activin A, and its receptors was analyzed by immunohistochemistry, polymerase chain reaction, and enzyme-linked immunosorbent assay. Functional vascular endothelial growth factor promoter analysis and gel shift assays were performed to define minimal promoter requirements and potential transcription factors. Nuclear expression and biochemical modifications of Sp1, as well as subcellular distribution, expression, and physical interaction of Smad proteins with Sp1, were assessed with immunoprecipitation and Western blot analysis. RESULTS: Hepatocellular carcinoma tumors and cell lines expressed activin A and its receptors. Activin A stimulated vascular endothelial growth factor gene transcription through Sp1-dependent induction of vascular endothelial growth factor promoter activity. Furthermore, activin A stimulated the DNA-binding and transactivation potential of Sp1. Immunoprecipitation showed activin A-dependent nuclear translocation of Smad2 and induction of Sp1/Smad2 interaction. The functional relevance of Sp1/Smad2 interaction was confirmed by transient transfection experiments, which showed that overexpression of Smad2 increased vascular endothelial growth factor promoter activity and endogenous vascular endothelial growth factor protein expression, whereas dominant negative Smad2 blocked activin A responsiveness. CONCLUSIONS: This study identifies activin A as a novel stimulus of vascular endothelial growth factor gene expression in hepatocellular carcinoma and delineates physical and functional cooperation of Sp1 and Smad2 as the underlying mechanism.

Transforming growth factor beta 1 stimulates vascular endothelial growth factor gene transcription in human cholangiocellular carcinoma cells.

The expression pattern and functional interaction of proangiogenic factors in human cholangiocellular carcinoma (CCC) have not been fully defined. We therefore investigated the expression of vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-beta 1 as well as their respective receptors in human CCC tumor samples and further analyzed their functional interaction in vitro. Expression of VEGF, TGF-beta 1, and their receptors was examined by immunohistochemistry, in situ hybridization, quantitative competitive reverse transcription-PCR, and ELISA. VEGF promoter analysis and identification of transcription factors involved in promoter regulation were investigated using transient transfection and electrophoretic mobility shift assays. We observed strong expression of VEGF in CCC tumor cells and localization of VEGF receptors 1 and 2 in endothelial cells; in addition, coexpression of TGF-beta 1 and its receptors in tumor cells suggests a possible functional interaction between both cytokines. In vitro studies confirmed a paracrine/autocrine stimulation of VEGF by TGF-beta 1 at a transcriptional level. Additional molecular studies using 5' deletion and mutational analysis of the human VEGF promoter revealed that TGF-beta 1 stimulates VEGF through Sp1-dependent transcriptional activation. These data suggest that overexpression and functional interaction of TGF-beta 1 and VEGF might contribute to the "angiogenic switch" and the malignant phenotype in human CCC.