Publications by authors named "Andreas G Niethammer"

Preclinical studies in animal models of obesity and inflammation have shown that oral administration of ARD-101, a potential TAS2R agonist, reduced food intake and body weight and downregulated inflammatory cytokines. We present results from a first-in-human phase 1 randomized, placebo-controlled trial that evaluated safety, pharmacokinetics, and pharmacodynamics of single or multiple ascending doses of oral ARD-101 (40, 100, and 240 mg) in healthy adults. A total of 43 subjects were randomly assigned and dosed to ARD-101 or placebo with 42 subjects completing the study treatment.

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VEGFR-2 is expressed on tumor vasculature and a target for anti-angiogenic intervention. VXM01 is a first in kind orally applied tumor vaccine based on live, attenuated Salmonella bacteria carrying an expression plasmid, encoding VEGFR-2. We here studied the safety, tolerability, T effector (Teff), T regulatory (Treg) and humoral responses to VEGFR2 and anti-angiogenic effects in advanced pancreatic cancer patients in a randomized, dose escalation phase I clinical trial.

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Background: The efficacy and safety of axitinib, a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors 1, 2, and 3 in combination with pemetrexed and cisplatin was evaluated in patients with advanced non-squamous non-small-cell lung cancer (NSCLC).

Methods: Overall, 170 patients were randomly assigned to receive axitinib at a starting dose of 5-mg twice daily continuously plus pemetrexed 500 mg/m(2) and cisplatin 75 mg/m(2) on day 1 of up to six 21-day cycles (arm I); axitinib on days 2 through 19 of each cycle plus pemetrexed/cisplatin (arm II); or pemetrexed/cisplatin alone (arm III). The primary endpoint was progression-free survival (PFS).

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Purpose: To prospectively determine the efficacy of combination therapy with temsirolimus plus bevacizumab versus interferon alfa (IFN) plus bevacizumab in metastatic renal cell carcinoma (mRCC).

Patients And Methods: In a randomized, open-label, multicenter, phase III study, patients with previously untreated predominantly clear-cell mRCC were randomly assigned, stratified by prior nephrectomy and Memorial Sloan-Kettering Cancer Center prognostic group, to receive the combination of either temsirolimus (25 mg intravenously, weekly) or IFN (9 MIU subcutaneously thrice weekly) with bevacizumab (10 mg/kg intravenously, every 2 weeks). The primary end point was independently assessed progression-free survival (PFS).

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Background: The investigational oral DNA vaccine VXM01 targets the vascular endothelial growth factor receptor 2 (VEGFR-2) and uses Salmonella typhi Ty21a as a vector. The immune reaction elicited by VXM01 is expected to disrupt the tumor neovasculature and, consequently, inhibit tumor growth. VXM01 potentially combines the advantages of anti-angiogenic therapy and active immunotherapy.

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Purpose: This multicenter, open-label, phase II study evaluated the safety and clinical activity of axitinib, a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors (VEGFR)-1, 2, and 3, in patients with metastatic melanoma.

Experimental Design: Thirty-two patients with a maximum of one prior systemic therapy received axitinib at a starting dose of 5 mg twice daily. The primary endpoint was objective response rate.

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Four novel oral DNA vaccines provide protection against melanoma, colon, breast, and lung carcinoma in mouse models. Vaccines are delivered by attenuated Salmonella typhimurium to secondary lymphoid organs and respectively target vascular endothelial growth factor receptor-2, transcription factor Fos-related antigen-1, anti-apoptosis protein survivin and Legumain, an asparaginyl endopeptidase specifically overexpressed on tumor-associated macrophages (TAMs) in the tumor microenvironment (TME). These vaccines are all capable of inducing potent cell-mediated protective immunity against self-antigens, resulting in marked suppression of tumor growth and dissemination.

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Objective: Vascular endothelial growth factor receptor 2 (VEGFR2)-overexpressing cells may form an interesting target for the treatment of atherosclerosis because of their involvement in processes that contribute to this disease, such as angiogenesis.

Methods And Results: We vaccinated mice against VEGFR2 by an orally administered DNA vaccine, comprising a plasmid, encoding murine VEGFR2, carried by live attenuated Salmonella typhimurium. This vaccine induces cellular immunity against cells that overexpress VEGFR2.

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Background: We analyzed the long-term results of patients with locally advanced rectal cancer using a multimodal approach consisting of total mesorectal excision (TME), intraoperative electron-beam radiation therapy (IOERT), and pre- or postoperative chemoradiation (CRT).

Patients And Methods: Between 1991 and 2003, 210 patients with locally advanced rectal cancer (65 International Union Against Cancer [UICC] Stage II, 116 UICC Stage III, and 29 UICC Stage IV cancers) were treated with TME, IOERT, and preoperative or postoperative CHT. A total of 122 patients were treated postoperatively; 88 patients preoperatively.

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Tumor-associated fibroblasts are key regulators of tumorigenesis. In contrast to tumor cells, which are genetically unstable and mutate frequently, the presence of genetically more stable fibroblasts in the tumor-stromal compartment makes them an optimal target for cancer immunotherapy. These cells are also the primary source of collagen type I, which contributes to decreased chemotherapeutic drug uptake in tumors and plays a significant role in regulating tumor sensitivity to a variety of chemotherapies.

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Purpose: To analyze long-term prognosis and morbidity after limb-sparing treatment of patients with extremity soft-tissue sarcoma, with intraoperative electron boost radiotherapy (IOERT) followed by a moderate dose of external beam radiotherapy (EBRT).

Methods And Materials: A total of 153 patients who were treated in a single center from 1991 to 2004 were evaluated. Median IOERT dose was 15 Gy, mean EBRT dose 43 Gy (range, 40-50.

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Purpose: Intraoperative electron-beam radiotherapy (IOERT) has been applied for local dose escalation in over 1,400 patients in Heidelberg since 1991. Among these were 30 children, in 18 of whom IOERT was employed in radiation treatment with external-beam radiotherapy (EBRT) on account of incomplete resection. We address the question whether IOERT is able to compensate for microscopic or macroscopic tumor residue if employed in the overall radiation regimen.

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The involvement of alpha(v)beta3 and alpha(v)beta5 integrins in angiogenesis and the use of integrin antagonists as effective antiangiogenic agents are documented. Radiotherapy is an important therapy option for cancer. It has been shown that ionizing radiation exerts primarily antiangiogenic effects in tumors but has also proangiogenic effects as the reaction of the tumor to protect its own vasculature from radiation damage.

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Acquired multidrug resistance (MDR) remains a major challenge in the treatment of cancer with chemotherapeutic drugs. It can be mediated by the up-regulated expression of different proteins within the tumor cell membrane. Here, we used murine multidrug resistance-1 (MDR-1) as a target-antigen for the immunotherapy of cancer.

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Four novel oral DNA vaccines provide long-lived protection against melanoma, colon, breast, and non-small cell lung carcinoma in mouse model systems. The vaccines are delivered by attenuated Salmonella typhimurium to secondary lymphoid organs and are directed against targets such as carcinoembryonic antigen, tyrosine-related protein, vascular endothelial growth factor receptor-2 [also called fetal liver kinase-1 (FLK-1)], and transcription factor Fos-related antigen-1 (Fra-1). The FLK-1 and Fra-1 vaccines are effective in suppressing angiogenesis in the tumor vasculature.

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Effective therapy of high-risk leukemia with established cytotoxic drugs may be limited by poor antitumor efficacy, systemic toxicity, and the induction of drug resistance. Here, we provide the first evidence that hydrolytically activated prodrugs may overcome these problems. For this purpose, VP16 was functionally blocked by hydrolytically cleavable carbonate linkers with unique characteristics to generate 2 novel prodrugs of VP16.

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Tumor cells are elusive targets for immunotherapy due to their heterogeneity and genetic instability. Here we describe a novel, oral DNA vaccine that targets stable, proliferating endothelial cells in the tumor vasculature rather than tumor cells. Targeting occurs through upregulated vascular-endothelial growth factor receptor 2 (FLK-1) of proliferating endothelial cells in the tumor vasculature.

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Development of tumor immunotherapies focuses on inducing autoimmune responses against tumor-associated self-antigens primarily encoded by normal, unmutated genes. We hypothesized that such responses could be elicited by T cell homeostatic proliferation in the periphery, involving expansion of T cells recognizing self-MHC/peptide ligands. Herein, we demonstrate that sublethally irradiated lymphopenic mice transfused with autologous or syngeneic T cells showed tumor growth inhibition when challenged with melanoma or colon carcinoma cells.

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