bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract C50: AST-6, a novel irreversible inhibitor of the epidermal growth factor receptor 1 and 2, inhibits tumor growth both in vitro and in vivo
Authors: Xie Hua , Lin Lipin , Tong Linjiang , Jiang Yong , Wang Yi , Zhang Xiaowei , Geng Meiyu , Guo Jianhui , Ding Jian 
Published: June 2012

Abstract
Despite the initial response to the reversible, ATP-competitive quinazoline inhibitors that target ErbB-family, such a subset of cancer patients almost invariably develop resistance. Recent compelling evidence demonstrated that irreversible ErbB inhibitors were significantly active to override this resistance. Several irreversible inhibitors are now under preclinical or clinical studies. Here, we found that AST-6, a rationally designed novel anilinoquinazoline compound, inhibited enzymatic activities of wild type EGFR and ErbB2 as well as EGFR L858R/T790M resistant mutant both in cell-free and cell-based levels. Importantly, AST-6 functions as an irreversible inhibitor, most likely by covalent modification of Cys 797 and Cys 805 in the catalytic domains of EGFR and ErbB2, respectively. Further studies showed that AST6 inactivated their downstream pathways and thereby inhibited the proliferation of a panel of cancer cell lines. Detailed insights manifested that ErbB2 expression experienced with a consistently higher sensitivity to AST-6 across various cell lines. And in parallel, ErbB2, but not EGFR, silencing in turn decrease the sensitivity of SK-OV-3 cells to AST-6. As a consequence, AST-6 caused a potent tumor growth inhibition in ErbB2-overexpressed SK-OV-3 human ovarian carcinoma and Calu-3 lung adenocarcinoma xenograft models, but weak suppression in EGFR-overexpressed tumor xenografts. The above findings, combined with a significant restriction of tumor growth challenged by AST6 in FVB-2/Nneu transgenic breast cancer mouse model, define AST-6 as a selective irreversible dual ErbB2 and EGFR inhibitor with ErbB2 being more sensitive.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C50.
Abstract C53: Dose-finding designs for combination therapies involving molecularly targeted agents
Authors: Mandrekar Sumithra J. , Qin Rui , Sargent Daniel J. 
Published: June 2012

Abstract
Purpose: Novel therapies are challenging current drug development standards. Agents with specific biologic targets, unknown dose-efficacy curves, limited toxicity profiles, and in combination therapy require novel statistical designs. We compared the operating characteristics of three model based designs incorporating both toxicity and a measure of efficacy to identify the optimal dose region for combination therapies.
Methods: Three designs were considered: continuation ratio model with a trinary outcome, bivariate logistic model treating toxicity and efficacy as independent outcomes, and bivariate probit model allowing for dependent toxicity and efficacy outcomes. All designs utilized a model-based methodology to adaptively determine dose escalation/de-escalation, based on the data observed to date in the trial. The model parameters were estimated using Markov chain Monte Carlo approach in a Bayesian framework. The target threshold for toxicity was set at 33%; the minimum and maximum sample sizes were set at 30 and 45, respectively, for the simulated trials; and the cohort size was 3 with at least nine patients needed to be treated at the proposed combination dose level. The performance of the designs was evaluated in simulation studies under six clinically relevant scenarios.
Results: As expected, the ability to correctly identify an optimal dose region was sensitive to the changes in the toxicity and/or efficacy across the dose level combinations. Considering 50% as a benchmark for the recommendation rate for the optimal dose or region (dose levels within 10% of the maximum efficacious dose level), at least one of the three models performed well in recommending the optimal dose region except when the dose-efficacy surface was non-monotone or the dose-toxicity surface was close to the target rate of 33%. All three models worked well in not recommending any dose combination when the starting dose level combination was too toxic. The median sample size across all scenarios ranged from 27–33.
Conclusions: Despite favorable operating characteristics, the implementation of these new designs in practice is challenging for a variety of reasons. Adoption of novel designs require a multi-pronged approach that provides a) clinically obvious advantages, b) practical design framework with a transparent decision making process, c) timely access to both toxicity and preliminary efficacy data, and d) portable user-friendly software, or very attentive statisticians.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C53.
Abstract C56: NCCTG phase I trial of everolimus (RAD001) and temozolomide (TMZ) in combination with radiation therapy (RT) in newly diagnosed glioblastoma multiforme (GBM) patients
Authors: Sarkaria Jann N. , Galanis Evanthia , Peller Patrick , Brown Paul , Wu Wenting , Felten Sara , Uhm Joon , Giannini Caterina , Jaeckle Kurt , Buckner Jan 
Published: June 2012

Abstract
Background: The mammalian target of rapamycin (mTOR) functions within the PI3K/Akt signaling pathway as a critical modulator of cell survival. We previously demonstrated significant synergy of the mTOR inhibitor sirolimus with RT in glioma xenografts. This Phase I study evaluated the safety and tolerability of combined therapy with the mTOR inhibitor RAD001, RT and TMZ.
Methods: All patients received weekly oral RAD001, starting 1 week prior to RT/TMZ and continuing until progression, with a break from therapy between RT/TMZ and adjuvant TMZ. RAD001 was dose escalated in cohorts of 6 patients. In addition to RAD001, all pts received standard treatment with RT (60 Gy)/TMZ (75 mg/m2 daily) and adjuvant TMZ (200 mg/m2 daily × 5 every 28 days). DLTs were defined during therapy with RAD001 combined with TMZ/RT.
Results: A total of 18 patients were enrolled. Combined RAD001/RT/TMZ was well tolerated at all dose levels with 1 of 6 patients with a DLT at each dose level. DLTs were Grade 3 fatigue (RAD001 25 mg/week), Grade 4 hematologic toxicity (RAD001 50 mg/week), and Grade 4 liver function elevation (RAD001 70 mg/week). With adverse event information available for all 18 patients, no grade 5 events were seen. Nine grade 4 events (thrombosis, fatigue, anemia, neutropenia, thrombocytopenia, leukopenia, SGPT (ALT), SGOT (AST), bilirubin elevation) were seen in 3 patients. On the basis of these results, the recommended Phase II dose currently being tested is RAD001 70 mg/week in combination with standard RT/TMZ and adjuvant TMZ. FDG PET scans were also obtained prior to the first dose of RAD001 and within 24 hours of the second dose of RAD001, prior to starting RT or TMZ, and changes in maximum standard uptake values (SUV) were compared between scans for each patient. Two patients at 25 mg RAD001/week had a 21% and 24% change in SUV, and 2 patients receiving 70 mg/week had a change in SUV uptake of −33% and −16%. Additional follow-up will be required to evaluate whether these SUV changes are associated with outcome.
Conclusions: RAD001 in combination with RT/TMZ and adjuvant TMZ was well tolerated, and the imaging results support continued evaluation of PET imaging as an early predictor of response to therapy.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C56.
Abstract C6: Phase 1 study of conatumumab (AMG 655), a proapoptotic death receptor-5 agonist antibody, in Japanese patients with advanced solid tumors
Authors: Murakami H. , Yamamoto N. , Boku N. , Onozawa Y. , Doi T. , Ohtsu A. , Fuse N. , Yoshino T. , Saito H. , Sasaki T. , Hsu M. , Gorski K. , Friberg G. 
Published: June 2012

Abstract
Background: Conatumumab is an investigational, fully human monoclonal agonist antibody that binds human death receptor-5 (DR5, TR-2), activates caspases, and induces apoptosis in sensitive tumor cells. The primary objectives of this phase 1 study were to assess the safety, tolerability, and pharmacokinetics (PK) of conatumumab in Japanese patients (pts) with advanced solid tumors.
Method: This is an open-label ascending dose study with a starting dose level of 3 mg/kg. Subsequent doses of 10 mg/kg and 20 mg/kg were planned. Six pts were enrolled into 1 of 3 dose cohorts (3, 10, or 20 mg/kg) of conatumumab administered intravenously once every 2 weeks as a single-agent. No conatumumab was administered on day 43 to allow assessment of terminal PK parameters. Conatumumab receptor occupancy on monocytes was assessed during the first treatment cycle. Pts remained on study until tumor progression or unacceptable toxicities occurred.
Results: Eighteen pts (6 in each dose cohorts) received at least 1 dose of conatumumab; 9 pts were men; median age was 58 years. Tumor types included: colorectal (5), non-small cell lung (4), gastric (2), soft tissue sarcoma (2) and one each of pancreatic cancer, thymoma, mesothelioma, rectal carcinoid and parotid cancer. The grade 3 adverse events included blood creatine phosphokinase increase, pain and increased lipase. One treatment emergent serious adverse event of pain was reported in cohort 2. This serious adverse event was not considered by the investigator to be related to conatumumab. There were no DLTs observed as defined in the protocol. No deaths occurred during treatment or the safety follow-up period. No subjects had an adverse event leading to conatumumab discontinuation. Conatumumab demonstrated dose-linear kinetics with a half-life of 12 to16 days. Pharmacokinetic profiles were similar to those in the Caucasian population. Tumor response data were available for all patients. A best response of stable disease (defined as a lack of progression at the first assessment at 8-weeks) was reported in 9 patients and progressive disease in 9 patients. Monocytes were found to express DR5, and showed a high degree of conatumumab receptor occupancy after treatment at all dose levels.
Conclusions: Conatumumab administered up to 20 mg/kg once every 2 weeks did not result in dose limiting toxicities in Japanese patients with advanced solid tumors. Adverse events and pharmacokinetics were similar to those in the first in human study conducted in the United States.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C6.
Abstract C61: The PI3K pathway inhibition in prostate cancer cells is enhanced by dual targeting with the mTOR inhibitor RAD001 and a mTOR/PI3K inhibitor leading to decreased cell proliferation and increased autophagy
Authors: Balakumaran Bala S. , Herbert James T. , Glover Wayne , Foye Adam , Pierobon Mariaelena , Petricoin Emanual , George Dan , Febbo Phillip G. 
Published: June 2012

Abstract
Introduction: Metastatic prostate cancer patients often become resistant to standard treatments such as androgen ablation therapy and docetaxel treatment and novel treatments are needed. Loss of PTEN and subsequent activation of the PI3K pathway is common in patients with advanced prostate cancer. However, use of mTOR inhibitors such as rapamycin analogues as single agents has had limited clinical impact and the identification of a potent therapeutic strategy for PI3K inhibition remains a critical question.
Experimental procedures: We have used gene expression data generated from metastatic tumors collected from patients with advanced prostate cancer both before and after treatment with RAD001 along with in vitro experiments in established prostate cancer cell lines to determine the impact of TORC1 inhibition, PI3K kinase inhibition, and dual inhibition on PI3K pathway signaling and cancer cell kinetics.
Summary: Treatment with RAD001 decreased tumor levels of pS6 but failed to result in a single clinical response. Gene set enrichment analysis of metastatic castration-resistant prostate cancer biopsies prior to and following treatment with RAD001 was associated with increased PI3K activity following treatment. Analysis of the activity of the downstream components of the PI3K/AKT pathway following RAD001 treatment showed reduced pS6 levels, had minimal impact on p4EBP1 levels, and increased phosphorylation of AKT1. Cytotoxic synergy is observed when RAD001 is combined with the PI3K inhibitor, LY294002 and dual PI3K/mTOR kinase inhibitors. These combinations result in more profound reduction of TORC1 activity resulting in decreased cell proliferation and increased autophagy but a continued persistence of pAKT. Reverse phase proteomics supports increased AKT activity in an androgen-receptor positive prostate cancer cell line treated with the combination as multiple AKT targets experience increased phosphorylation.
Conclusion: TORC1 inhibition results in an upregulation of PI3K activity and therapeutic combinations that inhibit both TORC1 and PI3K demonstrate cytotoxic synergy. The signaling manifestations of these combinations are a profound inhibition of TORC1 activity together with persistent phosphorylation and activity of AKT.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C61.
Abstract C64: Treatment with the Pim protein kinase inhibitor SMI-4a enhances AMPK phosphorylation, decreases Raptor levels, and blocks mTORC1 activity
Authors: Kraft Andrew S. , Beharry Zanna , Lin Ying-Wei , Mahajan Sandeep , Zemskova Marina , Xia Zuping , Smith Charles 
Published: June 2012

Abstract
We have identified a class of small molecule inhibitors of the Pim protein kinases, benzylidene thiazolidine-2-4 diones (J. Med. Chem. (2009) 52:74) with the most potent members having IC50s of 13 nM for Pim-1 and 2.3 µM for Pim-2. Compounds in this chemotype demonstrated selectivity of more than 2500-fold and 400-fold for Pim-1 or Pim-2 respectively while other congeners had equivalent potency towards both isozymes. In vivo, these molecules inhibited Pim kinase autophosphorylation and in a murine model inhibited the growth of subcutaneously implanted murine adenocarcinoma JC cells. One of the members of this chemotype, SMI-4a, has been shown to block the phosphorylation of the mTOR regulatory protein PRAS40 and subsequently the activity of the mTOR pathway (Mol. Cancer. Ther. (2009) 8: 1473; Cancer Biol. Ther. (2009) 8: 846). Now we show that the addition of SMI-4a to malignant cells increases the phosphorylation of AMPKα on Thr 172 in a LKB1-dependent manner, induces the phosphorylation of Raptor on Ser792, decreases the levels of Raptor protein, and inhibits mTORC1 activity. Immunoprecipitation of mTOR from SMI-4a treated cells consistently showed lower levels of bound Raptor and in vitro mTOR kinase assays from treated cells demonstrated a decreased ability to phosphorylate 4E-BP1. Knockdown of PIM-1 via siRNA in K562 leukemic cells showed increased AMPK phosphorylation and decreased Raptor protein levels, further demonstrating an important role for Pim kinase in regulating AMPK phosphorylation and Raptor levels. Additionally, mouse embryo fibroblasts (MEFs) deficient for Pim-1, Pim-2 and Pim-3 kinase (TKO MEFs) showed a significantly increased level of AMPK phosphorylation compared to wild type MEFs, which correlated with decreased mTORC1 activity and increased binding of 4E-BP1 with eIF-4E. The TKO MEFs grew significantly more slowly than wild type. The decreased mTORC1 activity correlated with an increase in the cellular level of AMP in TKO MEFs. Furthermore, the correlation between increased AMPK phosphorylation and a lower level of Raptor protein observed with SMI-4a treatment was also observed in TKO MEFs. Infection of TKO MEFs with lentiviruses expressing Pim 1 or Pim2 was able to reverse these effects, decreasing AMPK phosphorylation, and increasing Raptor protein levels. The cellular activity of mTORC1 was difficult to assess in TKO MEFs as we found substantially lower protein levels of the mTORC1 substrates 4E-BP1 and p70S6K. Akt was readily phosphorylated upon serum stimulation of TKO MEFs and mTORC2 activity was unchanged. Given the role of Pim kinase in regulating mTORC1 activity, we have combined SMI-4a and the mTOR inhibitor rapamycin inducing synergistic blockade of this pathway.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C64.
Abstract C65: Enhanced antitumor effect by the combination of a PI3K inhibitor ZSTK474 with an mTOR inhibitor rapamycin
Authors: Yoshimi Hisashi , Okamura Mutumi , Yamazaki Kanami , Yamori Takao 
Published: June 2012

Abstract
PI3K is a promising molecular target for the therapy of cancer. Various PI3K inhibitors are now under development. We developed a novel PI3K inhibitor ZSTK474 and demonstrated its potent antitumor efficacy. ZSTK474 is highly specific to PI3K and does not inhibit other kinases including mTOR that is a down stream component of PI3K pathway. The purpose of this study was to examine whether dual inhibition of PI3K and mTOR further improved antitumor efficacy. To assess the effect of the combination of ZSTK474 and rapamycin on prostate cancer PC-3 cells and lung cancer A549 cells in vitro, we used the isobologram method. The combination of ZSTK474 and rapamycin showed a supra-additive effect (synergism) on both PC-3 and A549.
We then evaluated the efficacy of the combination of ZSTK474 with an mTOR inhibitor rapamycin against the xenografts of PC-3 and A549. Suboptimal doses of ZSTK474 and rapamycin were determined as 100 mg/kg/day (p.o., from day 0 to day 14, except days 3 and 10) and 0.1 mg/kg/day (i.p., from day 0 to day 5 except day 3), respectively. Then, the combination of the two drugs was compared to the single drug treatments. The combination of ZSTK474 and rapamycin showed almost complete inhibition of the tumor growth whereas each single drug treatment showed partial inhibition. The synergy in the toxicity was not observed. We examined the effects of the combination on the PI3K/Akt downstream molecules in the PC-3 tumor tissues by immunohistochemical technique. The single treatment of ZSTK474 reduced the phosphorylation of Akt (Ser473), GSK3-beta and 4E-BP1, and partially reduced the phosphorylation of S6 and the expression of Cyclin D1. The single treatment of rapamycin reduced the phosphorylation of 4E-BP1, and partially reduced the phosphorylation of S6 and the expression of Cyclin D1, but did not reduce the phosphorylation of Akt (Ser473) or that of GSK3-beta. The combination of ZSTK474 and rapamycin reduced the phosphorylation of Akt, GSK3-beta, 4E-BP1 and S6, and the expression of Cyclin D1. These results confirmed the therapeutic efficacy of the combination of ZSTK474 and rapamycin against PC-3 xenografts. Therefore, the combination of PI3K inhibitor and mTOR inhibitor may be effective for cancer therapy.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C65.
Abstract C67: JFCR39 COMPARE system can predict molecular targets of phophatidylinositol 3-kinase inhibitors with high resolution
Authors: Kong Dexin , Dan Shingo , Yamazaki Kanami , Yamori Takao 
Published: June 2012

Abstract
JFCR39 COMPARE system is an anticancer drug-activity database that we established by exploiting a panel of 39 human cancer cell lines. Molecular target of an agent can be predicted by comparing its cell growth inhibition profiles (fingerprint) with those of anticancer drugs using the COMPARE program. As accumulating evidences suggest close involvement of phosphatidylinositol 3-kinase (PI3K) in various diseases, particularly in cancer, researchers in both industry and academics are in a race to develop PI3K inhibitors. Consequently, novel PI3K inhibitors such as ZSTK474, GDC-0941, NVP-BEZ235 and PI-103 have been developed in recent years. Even though all these inhibitors were reported to inhibit class I PI3K but not dozens of protein kinases, whether they have different molecular targets remained unknown. To predict such molecular target specificity, we have examined the fingerprints of these novel PI3K inhibitors and classical PI3K inhibitor LY294002 across JFCR39 panel, and analyzed the results using the COMARE system. Interestingly, we found highly similar fingerprints for ZSTK474 and GDC-0941 and cluster analysis distinguished them from the other three PI3K inhibitors, suggesting that ZSTK474 shared more in molecular targets with GDC-0941 than with any other PI3K inhibitors. To test this prediction, we determined their effects on PI3K superfamily (including classes I, II, and III PI3Ks, PI4K and PI3K-related kinases) by using several novel non-radioactive biochemical assays. As a result, ZSTK474 and GDC-0941 indicated highly similar inhibition profiles for PI3K superfamily, with class I PI3K inhibitory specificity much higher than the other three inhibitors, which supported the hypothesis derived from JFCR39 COMPARE result. In conclusion, JFCR39 system is able to provide valuable information regarding molecular target specificity, suggesting its utility in target identification with high resolution.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C67.
Abstract C75: A novel multi-targeted Aurora A and VEGFR2 kinase inhibitor, ENMD-2076, demonstrates synergistic antiproliferative and proapoptotic effects in combination with chemotherapy and trastuzumab in breast cancer cell lines
Authors: Diamond Jennifer R. , Eckhardt S Gail , Pitts Todd M. , Britt Blair C. , Kachaeva Maria I. , Varella-Garcia Marileila , Bray Mark R. , Fletcher Graham C. , Tentler John J. 
Published: June 2012

Abstract
Introduction: ENMD-2076 is an orally bioavailable small molecule kinase inhibitor with antiproliferative activity via Aurora A kinase inhibition, and antiangiogenic activity via VEGFR2 inhibition. ENMD-2076 is being studied in a phase I clinical trial in advanced solid tumors and has demonstrated a tolerable side-effect profile. Due to the involvement of both Aurora A and angiogenic signaling pathways in breast cancer, we explored the combination of ENMD-2076 and chemotherapy or anti-HER2 therapy against a panel of breast cancer cell lines.
Methods: Breast cancer cell lines were exposed to varying submicromolar concentrations of ENMD-2076 alone and in combination with carboplatin, docetaxel, or trastuzumab (HER2-overexpressing cell lines only). Proliferation was assessed using an SRB assay and analyzed using the Calcusyn program, whereby synergy was defined as a Combination Index of less than 1. FISH was performed to assess Aurora A gene amplification, VEGF concentrations were measured by ELISA, and apoptosis was analyzed using a caspase 3/7 assay.
Results: The combination of ENMD-2076 and carboplatin resulted in synergistic inhibition of proliferation in both HER2 + (BT-474, SKBr3, ZR-75-30) and in triple negative (MDA 231, MDA 468) breast cancer cell lines. Likewise, ENMD-2076 and trastuzumab resulted in robust synergistic growth inhibition in HER2 + breast cancer cell lines. Synergy was not observed with the ENMD-2076 and docetaxel combination. FISH analysis demonstrated that tumor cells were sensitive to ENMD-2076 regardless of levels of Aurora A amplification. An increase in apoptosis that was maximal at 72 hours was observed with single agent ENMD-2076 and the combinations with carboplatin or trastuzumab. Similarly, VEGF concentrations were decreased in response to treatment with ENMD-2076 alone or in combination with the other agents.
Discussion: These in vitro results demonstrate that ENMD-2076 acts synergistically with carboplatin to inhibit proliferation of triple negative breast cancer cell lines, and with both carboplatin and trastuzumab towards HER2+ breast cancer cell lines. This activity is associated with induction of cell death and reduction of VEGF secretion. These data are being confirmed in vivo using both trastuzumab-sensitive and trastuzumab-resistant xenograft models.
Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C75.