Eisai Research Institute andover

North Andover, MA, United States

Eisai Research Institute andover

North Andover, MA, United States
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Li Y.,Boehringer Ingelheim Pharmaceuticals | Lai W.G.,Boehringer Ingelheim Pharmaceuticals | Lai W.G.,Eisai Research Institute andover | Whitcher-Johnstone A.,Boehringer Ingelheim Pharmaceuticals | And 4 more authors.
Drug Metabolism and Disposition | Year: 2012

11-Ethyl-5,11-dihydro-5-methyl-8-[2-[(1-oxido-4-quinolinyl)oxy] ethyl]-6H-dipyrido[3,2-b:2′,3′-e][1,4]diazepin-6-one (BILR 355) is an inhibitor of the human immunodeficiency virus-1. BILR 355 exhibited a nonlinear pharmacokinetic profile and low exposure after oral administration to humans. This article describes the in vitro metabolism of BILR 355, which is correlated with the in vivo nonlinearity findings. Our in vitro studies had demonstrated that BILR 355 was extensively metabolized by cytochrome P450 3A. Thus, BILR 355 was concomitantly administered with ritonavir (RTV) in an attempt to boost systemic exposure, which did occur in humans. In addition, the expectation was that the overall metabolism of BILR 355 would be decreased with concomitant administration of RTV. Subsequent metabolite profiling was performed using human plasma samples obtained from clinical phase Ib studies with concomitant administration of BILR 355 and RTV. A total of 18 metabolites was observed. Their structures were proposed on the basis of high-performance liquid chromatography-tandem mass spectrometry technologies, and 10 metabolites were confirmed by comparison with synthetic standards. We were surprised to find that a disproportionate human metabolite, BILR 516, was uncovered during this metabolite profiling study and pharmacokinetic analysis of BILR 516 showed that it had a longer half-life and higher exposure than the parent compound at steady state. Of interest, BILR 516 was not detected in human plasma when BILR 355 was administered alone. Therefore, whereas RTV boosted the exposure of BILR 355, it resulted in a significant metabolic switching of BILR 355. Overall, this article demonstrates an unusual example of metabolic switching and raises concern about the consequence of metabolic switching during drug development. Copyright © 2012 by The American Society for Pharmacology and Experimental Therapeutics.

Li Y.,Boehringer Ingelheim Pharmaceuticals | Xu J.,Boehringer Ingelheim Pharmaceuticals | Xu J.,Eisai Research Institute andover | Lai W.G.,Boehringer Ingelheim Pharmaceuticals | And 2 more authors.
Drug Metabolism and Disposition | Year: 2012

Ritonavir (RTV) was used as a boosting agent to increase the clinical exposure of 11-ethyl-5,11-dihydro-5-methyl-8-[2-[(1-oxido-4-quinolinyl) oxy]ethyl]-6H-dipyrido[3,2-b:2′,3′-e][1,4]diazepin-6-one (BILR 355), an inhibitor of the human immunodeficiency virus, by inhibiting the CYP3A-mediated metabolism of BILR 355. However, although the levels of BILR 355 increased upon concomitant administration of RTV, a metabolite of BILR 355, BILR 516, which was not detected previously in humans dosed with BILR 355 alone, became a disproportionate human metabolite with levels exceeding the parent levels at steady state. This was an unusual finding based on the in vitro and in vivo metabolic profiles of BILR 355 available at that time. Our studies reveal that BILR 355 is reduced to an intermediate, BILR 402, by gut bacteria and the reduced metabolite (BILR 402) is then oxidized by aldehyde oxidase to form BILR 516, the disproportionate human metabolite. The role of aldehyde oxidase helped to explain the somewhat unique formation of BILR 516 in humans compared with preclinical animal species. This article underlines the increasing importance of two individually atypical enzymes in drug development, gut bacterial biotransformation and aldehyde oxidase, which in combination provided a unique metabolic pathway. In addition, this article clearly elucidates an example of novel metabolic switching and, it is hoped, raises awareness of the potential for metabolic switching in combination drug therapies. Copyright © 2012 by The American Society for Pharmacology and Experimental Therapeutics.

PubMed | Eisai Research Institute andover, University of Southern California, City of Hope Comprehensive Cancer Center, University of California at Davis and U.S. National Cancer Institute
Type: Clinical Trial, Phase I | Journal: Cancer chemotherapy and pharmacology | Year: 2015

The California Cancer Consortium completed a phase I trial of E7389 (eribulin mesylate), an analog of the marine natural product halichondrin B. This trial was to determine the pharmacodynamics, pharmacokinetics, and MTD of E7389 administered by bolus injection weekly for 3 weeks out of four.This trial included a rapid titration design. Real-time pharmacokinetics were utilized to guide dose escalation. Initially, single-patient cohorts were enrolled with intra- and inter-patient dose doubling. The second phase was a standard 3 + 3 dose escalation schedule. At the MTD, a cohort of patients was enrolled for target validation studies (separate manuscript). The starting dose was 0.125 mg/m(2), and doses were doubled within and between patients in the first phase. Blood and urine sampling for E7389 pharmacokinetics was performed on doses 1 and 3 of cycle 1. Levels were determined using a LC/MS/MS assay.Forty patients were entered. Thirty-eight were evaluable for toxicity and 35 for response. The rapid escalation ended with a grade 3 elevation of alkaline phosphatase at 0.5 mg/m(2)/week. The second phase ended at 2.0 mg/m(2)/week with dose-limiting toxicities of grades 3 and 4 febrile neutropenia. Other toxicities included hypoglycemia, hypophosphatemia, and fatigue. The MTD was 1.4 mg/m(2)/week. Responses included four partial responses (lung cancer [2], urothelial [1], and melanoma [1]).E7389 was well tolerated in this trial with the major toxicity being myelosuppression. PD shows that E7389 induces significant morphologic changes (bundle formation) in the microtubules of peripheral blood mononuclear cells and tumor cells in vivo. The data suggest that lower intra-tumoral levels of -tubulin III or higher intra-tumoral levels of MAP4 may correlate with response to E7389, while lower intra-tumoral levels of stathmin may be associated with progression. PK data reveal that E7389 exhibits a tri-exponential elimination from the plasma of patients receiving a rapid i.v. infusion. At sub-toxic doses, plasma concentrations of E7389 are maintained well above the levels required for activity in vitro for >72 h.

Yoneyama T.,Glycobiology Unit | Yoneyama T.,Hirosaki University | Angata K.,Glycobiology Unit | Angata K.,Japan National Institute of Advanced Industrial Science and Technology | And 5 more authors.
Molecular Biology of the Cell | Year: 2012

Glycans of α-dystroglycan (α-DG), which is expressed at the epithelial cell-basement membrane (BM) interface, play an essential role in epithelium development and tissue organization. Laminin-binding glycans on α-DG expressed on cancer cells suppress tumor progression by attenuating tumor cell migration from the BM. However, mechanisms controlling laminin-binding glycan expression are not known. Here, we used small interfering RNA (siRNA) library screening and identified Fer kinase, a non-receptor-type tyrosine kinase, as a key regulator of laminin-binding glycan expression. Fer overexpression decreased laminin- binding glycan expression, whereas siRNA-mediated down-regulation of Fer kinase increased glycan expression on breast and prostate cancer cell lines. Loss of Fer kinase function via siRNA or mutagenesis increased transcription levels of glycosyltransferases, including protein O-mannosyltransferase 1, β3-N-acetylglucosaminyltransferase 1, and like-acetylglucosaminyltransferase that are required to synthesize laminin-binding glycans. Consistently, inhibition of Fer expression decreased cell migration in the presence of laminin fragment. Fer kinase regulated STAT3 phosphorylation and consequent activation, whereas knockdown of STAT3 increased laminin-binding glycan expression on cancer cells. These results indicate that the Fer pathway negatively controls expression of genes required to synthesize lamininbinding glycans, thus impairing BM attachment and increasing tumor cell migration. © 2012 Yoneyama et al.

Lee K.-H.,Dana-Farber Cancer Institute | Lee K.-H.,Harvard University | Liu Y.-J.,Dana-Farber Cancer Institute | Biswas A.,Dana-Farber Cancer Institute | And 4 more authors.
Journal of Biological Chemistry | Year: 2011

Toll-like receptors (TLRs) and nucleotide-binding domain, leucine-rich repeat (NLR) proteins are two major forms of innate immune receptors that trigger inflammatory responses by various biological mechanisms such as cytokine production, recruitment of inflammatory cells, or activation of adaptive immunity. Although the innate immune system is designed to fight against infectious pathogens, excessive activation of TLR or NLR signaling pathways may lead to unwarranted inflammation with hazardous outcomes, including septic shock or inflammatory diseases. As part of the search for effective therapeutics to regulate these responses, here we show that a novel aminosaccharide compound, named DFK1012, inhibits immune responses caused by TLR and NLR activation. Treatment with DFK1012, but not its derivatives DFK845 or DFK846, strongly inhibited pro-inflammatory cytokine production upon stimulation via either TLR or NLR proteins in macrophages. Importantly, we have not observed cytotoxicity in any range of its working concentration. Treatment with DFK1012 did not interfere with TLR- or NLR-induced activation of p38 and JNK, phosphorylation/degradation of IκB, and subsequent nuclear translocation of NF-κB subunit p65, suggesting that the inhibitory activity of DFK1012 is not due to the suppression of downstream signaling. Indeed, DFK1012 did not impair transcription of pro-inflammatory cytokine genes but rather promoted post-translational degradation of pro-inflammatory cytokines. Therefore, DFK1012 is a novel anti-inflammatory compound that drives proteolysis of proinflammatory cytokines induced by TLR and NLR stimulation. DFK1012 may represent a novel class of potential therapeutic agents aimed at the treatment of inflammatory disorders. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.

Singh M.,Novartis | Kazzaz J.,Novartis | Ugozzoli M.,Novartis | Baudner B.,Novartis | And 5 more authors.
Human Vaccines and Immunotherapeutics | Year: 2012

The inclusion of a potent TLR4 immune potentiator to a recombinant antigen vaccine formulation enhances both the magnitude and the breadth of the engendered immune response. One such immune potentiator (TLR4 agonist E6020) was evaluated with recombinant Men B antigens delivered in MF59 sub-micron adjuvant emulsion. The ability of this formulation to enhance serum antibody and bactercidal titers was investigated. The co-delivery of E6020 within MF59 enhanced both the serum and bactericidal titers for Men B antigens and for Men B antigens combined with Men ACWY-CRM conjugate vaccine. The delivery of TLR4 agonist within MF59 emulsion oil droplets leads to a more potent response in comparison to the TLR4 when admixed with MF59 emulsion. © 2012 Landes Bioscience.

Wang S.,Georgetown University | Astsaturov I.A.,Fox Chase Cancer Center | Bingham C.A.,Fox Chase Cancer Center | McCarthy K.M.,Fox Chase Cancer Center | And 9 more authors.
Cancer Immunology, Immunotherapy | Year: 2012

Toll-like receptors are potent activators of the innate immune system and generate signals leading to the initiation of the adaptive immune response that can be utilized for therapeutic purposes. We tested the hypothesis that combined treatment with a Toll-like receptor agonist and an antitumor monoclonal antibody is effective and induces host-protective antitumor immunity. C57BL/6 human mutated HER2 (hmHER2) transgenic mice that constitutively express kinase-deficient human HER2 under control of the CMV promoter were established. These mice demonstrate immunological tolerance to D5-HER2, a syngeneic human HER2-expressing melanoma cell line. This human HER2-tolerant model offers the potential to serve as a preclinical model to test both antibody therapy and the immunization potential of human HER2-targeted therapeutics. Here, we show that E6020, a Toll-like receptor-4 (TLR4) agonist effectively boosted the antitumor efficacy of the monoclonal antibody trastuzumab in immunodeficient C57BL/6 SCID mice as well as in C57BL/6 hmHER2 transgenic mice. E6020 and trastuzumab co-treatment resulted in significantly greater inhibition of tumor growth than was observed with either agent individually. Furthermore, mice treated with the combination of trastuzumab and the TLR4 agonist were protected against rechallenge with human HER2-transfected tumor cells in hmHER2 transgenic mouse strains. These findings suggest that combined treatment with trastuzumab and a TLR4 agonist not only promotes direct antitumor effects but also induces a host-protective human HER2-directed adaptive immune response, indicative of a memory response. These data provide an immunological rationale for testing TLR4 agonists in combination with antibody therapy in patients with cancer. © 2011 Springer-Verlag.

Smith J.A.,University of California at Santa Barbara | Wilson L.,University of California at Santa Barbara | Azarenko O.,University of California at Santa Barbara | Zhu X.,Eisai Research Institute andover | And 4 more authors.
Biochemistry | Year: 2010

Eribulin mesylate (E7389), a synthetic analogue of the marine natural product halichondrin B, is in phase III clinical trials for the treatment of cancer. Eribulin targets microtubules, suppressing dynamic instability at microtubule plus ends through an inhibition of microtubule growth with little or no effect on shortening [Jordan,M. A., et al. (2005) Mol. Cancer Ther. 4, 1086-1095]. Using [3H]eribulin, we found that eribulin binds soluble tubulin at a single site; however, this binding is complex with an overall Kd of 46 μM, but also showing a real or apparent very high affinity (Kd = 0.4 μM) for a subset of 25% of the tubulin. Eribulin also binds microtubules with a maximum stoichiometry of 14.7 ± 1.3 molecules per microtubule (Kd = 3.5 μM), strongly suggesting the presence of a relatively high-affinity binding site at microtubule ends. At 100 nM, the concentration that inhibits microtubule plus end growth by 50%, we found that one molecule of eribulin is bound per two microtubules, indicating that the binding of a single eribulin molecule at a microtubule end can potently inhibit its growth. Eribulin does not suppress dynamic instability at microtubule minus ends. Preincubation of microtubules with 2 or 4 μM vinblastine induced additional lower-affinity eribulin binding sites, most likely at splayed microtubule ends. Overall, our results indicate that eribulin binds with high affinity to microtubule plus ends and thereby suppresses dynamic instability. © 2010 American Chemical Society.

PubMed | Eisai Research Institute andover
Type: Journal Article | Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology | Year: 2016

2012 Background: Resistance to tubulin-targeted agents has been associated with differential tubulin isotype expression in cancer cells. In this study we investigated whether -tubulin isotype composition of tumor cells affects their sensitivity to 2 natural product-based antitubulin agents: halichondrin analog E7389 and hemiasterlin analog E7974.Antiproliferative effects of E7389, E7974, paclitaxel and vinblastine against a panel of human breast cancer cell lines were determined by methylene blue-based or MTT-based cell growth inhibition assays. Cell lines were tested for evidence of PgP expression by monitoring effects of the PgP blocker verapamil on paclitaxel sensitivity. Using quantitative PCR with specific primers, expression levels of the seven human -tubulin isotypes were determined (I, II, III, IVa, IVb, V, and VI).No evidence for PgP expression was found in any of the cell lines tested. In growth inhibition studies, interdrug correlations were seen between sensitivities to the 3 microtubule polymerization inhibitors E7974, E7389 and vinblastine, but not between the microtubule stabilizer paclitaxel and the other agents. All 7 -tubulin isotypes were detected at different levels in each cell line, with isotypes I and IVb showing the least variation while isotypes II, III, and IVa showed the greatest variability between the cell lines. A significant correlation was demonstrated between III tubulin expression levels and sensitivity to both E7389 and E7974.These findings in cancer cell lines suggest that tumors expressing higher levels of III tubulin isotype may be more responsive to treatment with E7389 and E7974. If confirmed clinically, such preclinical insights may lay the foundation for selection of patient populations with enhanced sensitivities to these 2 natural product-based antitubulin agents. [Table: see text].

PubMed | Eisai Research Institute andover
Type: | Journal: Current protocols in pharmacology | Year: 2012

The growth of new blood vessels, or angiogenesis, is a naturally occurring process in both health and disease states. An area of active research, regulation of angiogenesis, is being studied as an approach for the treatment of cancer and a range of other disorders having vascular proliferation as a component. The process of angiogenesis is very complex and occurs in multiple steps, with a major involvement of endothelial cells. Various in vivo models have been developed to assess inhibitors of angiogenesis. As these are generally technically difficult and labor intensive, with observed effects difficult to quantify, they do not lend themselves to compound screening. Rather they are used for confirmatory studies. In contrast, in vitro assays developed to model various steps in the angiogenesis process are easy to perform and lend themselves to high-throughput analysis. Described in this unit is an in vitro assay that can be employed to investigate endothelial differentiation inhibitors through assessment of their effects on capillary tube formation by endothelial cells on Matrigel.

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