Oncology Compounds Research Articles

Bioluminescent, Nonlytic, Real-Time Cell Viability Assay and Use in Inhibitor Screening.

Real-time continuous monitoring of cellular processes offers distinct advantages over traditional endpoint assays. A comprehensive representation of the changes occurring in live cells over the entire length of an experiment provides information about the biological status of the cell and informs decisions about the timing of treatments or the use of other functional endpoint assays. We describe a homogeneous, nonlytic, bioluminescent assay that measures cell viability in real time. This time-dependent measurement allowed us to monitor cell health for 72 h from the same test samples, distinguish differential cell growth, and investigate drug mechanism of action by analyzing time- and dose-dependent drug effects. The real-time measurements also allowed us to detect cell death immediately (>75% signal decrease within 15 min of digitonin addition), analyze drug potency versus efficacy, and identify cytostatic versus toxic drug effects. We screened an oncology compound library (Z′ = 0.7) and identified compounds with varying activity at different time points (1.6% of the library showed activity within 3 h, whereas 35.4% showed a response by 47 h). The assay compared well with orthogonal endpoint cell viability assays and additionally provided data at multiple time points and the opportunity to multiplex assays on the same cells. To test the advantage of time-dependent measurements to direct optimal timing of downstream applications, we used the real-time cell viability assay to determine the ideal time to measure caspase activity by monitoring the onset of cell death and multiplexing a luminescent caspase activation assay on the same test samples.

Monoclonal antibodies — A new era in the treatment of multiple myeloma

Monoclonal antibodies (mAbs) are currently the most investigated therapeutic compounds in oncology, but there is no monoclonal antibody approved in the treatment of multiple myeloma (MM). Nevertheless several really promising molecules are under investigation in phase III clinical trials. Dominantly daratumumab (anti-CD38) and elotuzumab (anti-CS1) showed extraordinary effectiveness in phase I/II trials. The toxicity was acceptable which is important for their addition to standard anti-myeloma agents like proteasome inhibitors or immunomodulatory drugs. Monoclonal antibodies such as denosumab (anti-RANKL) or BHQ880 (anti-DKK-1) are investigated also in the management of myeloma bone disease. This review is focused on the most promising mAbs, their mechanisms of action and the rationale of use. Practically all available results have been described. If the ongoing trials confirm the efficacy and safety of mAbs, they would become an important part of MM treatment that would be translated in the further improvement of therapeutic outcomes.

Abstract POSTER-TECH-1111: High-throughput drug sensitivity and resistance testing of ovarian cancer cell lines provides useful strategy for assessing drug repositioning and therapeutic possibilities of emerging drugs

Abstract As almost all therapeutic approaches for ovarian cancer (OC) are organ-based therapies that have been tested in large-scale clinical studies, no precision medicine approach to OC currently exists. There is an urgent need to develop a better understanding of the drug responsiveness in OC, particularly in the clear cell and mucinous subtypes, which tend to be resistant to the commonly used platinum-based regimens. This would help to improve survival and facilitate precision medicine therapy approaches. In order to discover previously unsuspected anti-cancer effects of approved and emerging drugs, we applied Drug Sensitivity and Resistance Testing (DSRT) technology (Pemovska et al., Cancer Discovery, 2013) to determine detailed dose-response effects of 306 drugs in 29 established OC cell lines (12 clear cell, 6 mucinous, 1 endometrioid, and 10 serous and other OC cell lines). The panel covered 137 approved drugs as well as emerging, investigational and pre-clinical oncology compounds such as kinase and non-kinase inhibitors. All drugs were tested at 5 different concentrations, covering a 10,000-fold concentration range by using Labcyte nano-dispensing technology, in order to generate detailed dose-response curves for each drug in each cell line. The area under the curve was estimated from the dose-response curve to obtain the drug sensitivity score. Bioinformatic processing of the drug response data from OC cell lines resulted in several key observations. First, the clusters did not depend on the histological origin of the OC cell lines but were clustered according to drug categories. Second, our result showed that many emerging or non-approved drugs were sensitive in subgroups of OC cell lines. For example, MEK inhibitors and mTOR inhibitors show high sensitivity in many OC cell lines. They can be candidates for drug repositioning. Third, we confirmed reproducibility of our findings. In summary, as per the data from direct testing of drug efficacy, several emerging anti-cancer drugs show potential responses in subsets of OC cell lines. DSRT technology provides a powerful strategy for assessing drug response in OC cell models, and it could also help asses drug responses in patient-derived ex vivo model systems of OC. Analysis of correlations of DSRT data with genomic data of the cell lines is underway and will yield new translational and pharmacogenomic opportunities for treating OC. Citation Format: Akira Hirasawa, Astrid Murumägi, Mariliina Arjama, Bhagwan Yadav, John Patrick Mpindi, Krister Wennerberg, Tero Aittokallio, Daisuke Aoki, Olli Kallioniemi. High-throughput drug sensitivity and resistance testing of ovarian cancer cell lines provides useful strategy for assessing drug repositioning and therapeutic possibilities of emerging drugs [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-TECH-1111.

Abstract 1469: Patient derived xenograft (PDX) models: improving predictability of experimental cancer therapies

Abstract Clinical development of cancer therapies is associated with attrition rates as high as 80-95%. This high attrition suggests that standard preclinical pharmacology models do not accurately reflect clinical responses. The development of more predictive preclinical models requires several considerations; the relevance of the in vivo model, the administration of test agent, and the interpretation of efficacy data. PDX are cancer models developed from the direct transfer of patient tumor tissue into immunocompromised mice. A collection of PDX models, by retaining the genetic and histologic characteristics of the patients from which they were derived, represents the complexity and heterogeneity of human cancer. To minimize the clinical attrition rates of oncology compounds, we are developing hundreds of PDX models in seven major cancer indications. The collection is being molecularly profiled by RNAseq, WES, and proteomics. Profiling has identified models with robust expression of target proteins or mutant oncogenes that are likely to respond in preclinical efficacy tests. Conversely, the PDX models may provide an understanding of resistance, for example evaluating models with good target expression that fail to respond to therapy. Patient and tumor information, if known, has been collected for each PDX model including age, sex, cancer stage and grade, diagnosis, primary or metastatic site, and prior treatments. In addition to the improvements provided by the PDX models, a preclinical paradigm shift away from treatment with maximally tolerated dose towards clinically relevant dose (CRD), taking into consideration such aspects as exposure, formulation, route and schedule, is critical when attempting to predict clinical outcome from preclinical data. Also essential is the incorporation of clinically meaningful endpoints (regression) when assessing preclinical activity. We have initiated studies on cohorts of non small cell lung and breast PDX models to predict the likely clinical efficacy of candidate compounds for clinical development and to determine the CRD for standard of care (SOC) regimens required to define the most promising Phase II/III combination therapies. Anti-tumor activities were characterized using RECIST criteria of progressive disease (PD), stable disease (SD), partial response (PR), and complete response (CR). Target expression was evaluated by RNA, proteomics and immunohistochemistry. Preliminary results demonstrate a spectrum of responses against experimental therapeutics, including Phase I ADCs and are defining the CRD required for combination treatments with SOC. Identification of the most critical parameters of PDX models predicting clinical outcome will help in validating the utility of ‘n of 1′ studies with the PDX collection, inform patient enrollment strategies, guide combination therapies, and provide insight for identifying new tumor indications. Citation Format: Edward Rosfjord, Xin Han, Danielle Leahy, Erik Upeslacis, Justin Lucas, Jonathon Golas, Andrea Hooper, Fred Immermann, Bingwen Lu, Jeremy Myers, Zhengyan Kan, James Hardwick, Eric Powell, Puja Sapra, Paul Rejto, Hans-Peter Gerber, Judy Lucas. Patient derived xenograft (PDX) models: improving predictability of experimental cancer therapies. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1469. doi:10.1158/1538-7445.AM2015-1469

Sources and Targets for Drug Repurposing: Landscaping Transitions in Therapeutic Space.

Patent applications provide unique opportunities for landscaping ongoing medical innovation. In this analysis of drug repurposing patent applications published under the international Patent Convention Treaty during the years 2011-2014, we discuss what categories in the World Health Organization's International Classification of Diseases provide drugs and drug candidates for potential second medical uses, and how these proposed repurposed uses relate to each other and the original ones. Also discussed are the geographic origin of the patent assignees and their type and size. Beyond the expected interactions within the field of neuropsychiatry, frequent secondary use claims for oncology compounds to treat noninfectious respiratory diseases, and for cardiovascular compounds to treat neurological conditions, were unexpected findings derived from the repurposing heatmap. The relative absence of repurposing claims to treat parasitic or tropical diseases contrasts sharply with the broad attention this segment receives in the peer-reviewed literature. Equally notable are the dominance of universities and small pharmaceutical companies; a focus of large multinational companies to repurpose their own compounds; and the leading role of European-centered entities among the assignees. We believe that this investigation represents the first comprehensive cross-sectional attempt at mapping drug repurposing patterns across therapeutic fields, and could provide important clues that complement those obtained from the peer-reviewed literature.

Radiation Parameters of Some Potential Bioactive Compounds.

In this study, we aimed to determine the radiation parameters of some potential bioactive compounds. 1-Aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were synthesized via classical conventional heating method. Aryl part was changed as phenyl (C6H5), 4-methylphenyl (4-CH3C6H4), 4-fluorophenyl ( 4-FC6H4), 4-nitrophenyl (4-NO2C6H4), 4-chlorophenyl (4-ClC6H4), 4-bromophenyl (4-BrC6H4), and 2-thienyl (C4H3S-2-yl). Mass attenuation coefficient (μm), effective atomic number (Z(eff)) and effective electron density (N(el)) of compounds were determined experimentally and theoretically for at 8.040, 8.910, 13.40, 14.96, 17.48, 19.61, 22.16, 24.94, 32.19, 36.38, 44.48, 50.38 and 59.54 keV photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. Radiation parameters of these compounds which can be anti-cancer drug candidate were given in the tables. The results show that phenyl ring behave like thiophene ring in terms of radiation absorption. It is thought that the results of study may drive allow the development of drug candidate new compounds in medical oncology.

Fyn inhibition rescues established memory and synapse loss in Alzheimer mice.

Currently no effective disease-modifying agents exist for the treatment of Alzheimer disease (AD). The Fyn tyrosine kinase is implicated in AD pathology triggered by amyloid-ß oligomers (Aßo) and propagated by Tau. Thus, Fyn inhibition may prevent or delay disease progression. Here, we sought to repurpose the Src family kinase inhibitor oncology compound, AZD0530, for AD. The pharmacokinetics and distribution of AZD0530 were evaluated in mice. Inhibition of Aßo signaling to Fyn, Pyk2, and Glu receptors by AZD0530 was tested by brain slice assays. After AZD0530 or vehicle treatment of wild-type and AD transgenic mice, memory was assessed by Morris water maze and novel object recognition. For these cohorts, amyloid precursor protein (APP) metabolism, synaptic markers (SV2 and PSD-95), and targets of Fyn (Pyk2 and Tau) were studied by immunohistochemistry and by immunoblotting. AZD0530 potently inhibits Fyn and prevents both Aßo-induced Fyn signaling and downstream phosphorylation of the AD risk gene product Pyk2, and of NR2B Glu receptors in brain slices. After 4 weeks of treatment, AZD0530 dosing of APP/PS1 transgenic mice fully rescues spatial memory deficits and synaptic depletion, without altering APP or Aß metabolism. AZD0530 treatment also reduces microglial activation in APP/PS1 mice, and rescues Tau phosphorylation and deposition abnormalities in APP/PS1/Tau transgenic mice. There is no evidence of AZD0530 chronic toxicity. Targeting Fyn can reverse memory deficits found in AD mouse models, and rescue synapse density loss characteristic of the disease. Thus, AZD0530 is a promising candidate to test as a potential therapy for AD.

Sources and Targets for Drug Repurposing: Landscaping Transitions in Therapeutic Space

Patent applications provide unique opportunities for landscaping ongoing medical innovation. In this analysis of drug repurposing patent applications published under the international Patent Convention Treaty during the years 2011–2014, we discuss what categories in the World Health Organization's International Classification of Diseases provide drugs and drug candidates for potential second medical uses, and how these proposed repurposed uses relate to each other and the original ones. Also discussed are the geographic origin of the patent assignees and their type and size. Beyond the expected interactions within the field of neuropsychiatry, frequent secondary use claims for oncology compounds to treat noninfectious respiratory diseases, and for cardiovascular compounds to treat neurological conditions, were unexpected findings derived from the repurposing heatmap. The relative absence of repurposing claims to treat parasitic or tropical diseases contrasts sharply with the broad attention this segment receives in the peer-reviewed literature. Equally notable are the dominance of universities and small pharmaceutical companies; a focus of large multinational companies to repurpose their own compounds; and the leading role of European-centered entities among the assignees. We believe that this investigation represents the first comprehensive cross-sectional attempt at mapping drug repurposing patterns across therapeutic fields, and could provide important clues that complement those obtained from the peer-reviewed literature.

Abstract 1792: Identification of synergistic drug combinations with the oral HSP90 inhibitor Debio 0932 in non-small cell lung cancer and renal cell cancer

Abstract Background: Drug resistance is a major problem in cancer therapy, which can be addressed by simultaneously targeting multiple critical nodes of the signalling networks controlling growth and survival of cancer cells. One such approach is to target heat shock protein 90 (HSP90), a chaperone for many potent oncogenic proteins involved in proliferation, survival, invasion, metastasis and angiogenesis. Pharmacologic inhibition of HSP90 results in the proteasomal degradation of client oncoproteins thereby eliminating their oncogenic activity. The oral HSP90 inhibitor Debio 0932 displays favorable pharmacologic features. The goal of this study was to identify novel synergistic drug combinations for Debio 0932 in non-small cell lung cancer (NSCLC) and renal cell cancer (RCC) which would support the clinical development of Debio 0932 in those two indications. Material and Methods: For NSCLC, an in vitro high-throughput combination screen was performed using 6 human NSCLC cell lines bearing various genetic alterations, where Debio 0932 was combined pairwise with 128 commercially available oncology compounds in a cell viability assay. Some additional compounds not included in the panel were also tested independently. For RCC, combination of Debio 0932 with several selected standard-of-care drugs was analyzed on a panel of 8 human RCC cell lines. Synergy was assessed by using an AUC-based curve shift analysis method or according to the Chou-Talalay equation. A selection of synergistic drug combinations was further studied using tumor xenograft mouse models of human NSCLC and RCC. Results: In NSCLC, anti-proliferative synergism with Debio 0932 was observed in vitro in combination with the standard-of-care drugs docetaxel, paclitaxel or gemcitabine, as well as with mTOR inhibitors. In RCC cell lines, combinations of Debio 0932 with RCC standard-of-care drugs also displayed anti-proliferative synergy. The synergy observed in vitro was further confirmed in mouse xenografts of human NSCLC and RCC cell lines, where the drug combinations caused marked anti-tumor activity that was superior to either monotherapy. Conclusion: Several synergistic drug combinations were identified for the HSP90 inhibitor Debio 0932 in NSCLC and RCC. These findings underline the feasibility of using in vitro high-throughput screening for the discovery of novel drug combinations with increased in vivo anti-tumor efficacy . Furthermore, they provide a rationale for the combination of Debio 0932 with standard-of-care drugs in NSCLC and RCC and are the basis for ongoing clinical trials in several cancer types. Citation Format: Casey G. Langdon, Norbert Wiedemann, Hélène Maby-El Hajjami, Mathew A. Held, James T. Platt, Grégoire Vuagniaux, Marcus W. Bosenberg, David F. Stern, Frédéric Lévy. Identification of synergistic drug combinations with the oral HSP90 inhibitor Debio 0932 in non-small cell lung cancer and renal cell cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1792. doi:10.1158/1538-7445.AM2014-1792

Abstract 3674: Targeted oncology therapeutics show unique cardiotoxic profiles: Ponatinib as a case study

Abstract Although tyrosine kinase inhibitors (TKI) have greatly improved the treatment and prognosis of multiple cancer types, unexpected clinical cardiotoxicity has occurred with some of these agents that was not predicted by standard preclinical toxicity assessment methods. Since cardiotoxicity with TKI are often caused by the inhibition of signaling pathways that are critical to cardiac cell function, multi-targeted TKI that block multiple pathways increase the likelihood for cardiac cell damage. We recently demonstrated that an in vitro multi-parameter test panel assessing the effect of drug treatment on overall cardiac health and function could accurately predict the cardiotoxicity of four FDA-approved TKI. The multi-targeted TKI that are clinically associated with cardiac adverse events (crizotinib, sunitinib, nilotinib) all proved to be cardiotoxic in our in vitro tests while a more targeted and relatively cardiac-safe drug, erlotinib, showed only minor changes in cardiac cell health. The present studies expand upon this initial observation using a broad panel of drugs such as TKI (including the recently withdrawn TKI ponatinib), chemotherapeutic agents, and non-oncology compounds, which were grouped based on their known clinical toxicity profiles ranging from cardiac safe to withdrawn. We assessed each compound's cardiotoxic potential by examining their effect on cell viability, reactive oxygen species (ROS) generation, lipid formation, troponin secretion and beating activity in a human induced pluripotent-derived cardiac stem (iPS) cell model. The results showed a unique cardiotoxic signature of oncology therapeutics that was significantly different from other drug classes. Oncology compounds, including ponatinib, induced metabolic stress (ROS generation and lipid formation) resulting in potent cardiac cell death and troponin secretion while other classes of drugs disrupted cardiac cell beating with minimal impact on cardiac cell health. In comparison, cardiac-safe drugs, including non-oncology compounds and more targeted TKI, did not impact any of the endpoints that assessed cardiac cell health and function. Our results demonstrate unique toxicity profiles for different drug classes which may reflect multiple mechanisms of cardiotoxicity. For oncology compounds specifically, multi-targeted TKI and chemotherapeutic agents show potent cardiac toxicity while more targeted agents are less cardiac toxic. These studies show that a multi-parameter approach provides a comprehensive and robust assessment of cardiotoxic potential by evaluating several parameters that are important to cardiac cell health and function in a more predictive adult cardiac cell model. A panel such as this aids in early risk assessment of cardiotoxic compounds and may reduce drug failure due to toxicity discovered in later phases of development or after drug approval such as that shown with ponatinib. Citation Format: Dominique Talbert, Kimberly Doherty, Patricia Trusk, Diarmuid Moran, Scott Shell, Sarah Bacus. Targeted oncology therapeutics show unique cardiotoxic profiles: Ponatinib as a case study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3674. doi:10.1158/1538-7445.AM2014-3674

Abstract 4763: The tyrosine kinase inhibitor axitinib targets T315I gatekeeper-mutant Philadelphia chromosome-positive leukemias in vitro and in vivo

Abstract The use of ABL1 kinase inhibitors has dramatically improved the outcome for chronic myeloid leukemia (CML) and Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) patients. However, resistance after treatment still poses a major clinical challenge. The most common resistance mechanism following treatment with first or second line therapy is the occurrence of a T315I mutation in the kinase domain of BCR-ABL1. Only one clinically available ABL1 inhibitor, ponatinib, has been shown to target this gatekeeper mutation, but has recently been associated with significant adverse effects. Hence, there is an unmet need for new and improved therapies for patients with T315I BCR-ABL1 leukemias. In this study we set out to functionally and molecularly profile BCR-ABL1 T315I-driven CML/Ph+ALL patient samples to understand the disease pathogenesis and identify novel therapies with a drug sensitivity and resistance testing (DSRT) platform covering 306 approved and investigational oncology compounds. Mononuclear cells isolated from patient bone marrow were plated with drugs on 384-well plates. Each compound was tested for its effect on cell growth and survival in a 10,000-fold concentration range enabling the generation of dose response curves and by comparing to healthy donor mononuclear cells, selective drug sensitivity scores (sDSS). Ex vivo DSRT results of one CML and two Ph+ALL patient samples with the T315I mutation revealed a marked and specific sensitivity (IC50 30-40nM) to the tyrosine kinase inhibitor axitinib, originally developed as a VEGFR inhibitor. Strikingly, sensitivity to axitinib was higher in these T315I positive patient samples than in T315I negative CML or ALL patient samples or any other leukemic samples. Supporting the notion that axitinib is a direct T315I BCR-ABL1 inhibitor we observed that Ba/F3 cells transformed with T315I BCR-ABL1 were sensitive to axitinib while the same cells transformed with wild type BCR-ABL1 were not. Finally, we discovered that axitinib has been described to have selective binding towards T315I ABL1 compared to the wild type kinase (Kd 1.5 nM vs. 36 nM, respectively, Davis et al. 2011, Nat. Biotechnol. 29:1046-1051). Based on this information, the T315I CML patient mentioned above was compassionately treated with axitinib for 2 weeks resulting in a rapid 4-fold reduction of the mutated transcript levels in blood suggesting targeted in vivo activity of the drug. In summary, we demonstrated that axitinib is a potent BCR-ABL1 T315I inhibitor both in vitro and in vivo. In light to the fact that axitinib is currently approved as a second line therapy for renal cell carcinoma and is well tolerated in patients, there is an opportunity to repurpose axitinib for Ph+ leukemia patients with T315I mutations with significantly shorter clinical development time. Citation Format: Tea Pemovska, Mika Kontro, Gretchen A. Repasky, Kimmo Porkka, Krister Wennerberg. The tyrosine kinase inhibitor axitinib targets T315I gatekeeper-mutant Philadelphia chromosome-positive leukemias in vitro and in vivo. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4763. doi:10.1158/1538-7445.AM2014-4763

Abstract 5384: Systematic high-throughput drug sensitivity and resistance testing (DSRT) of ovarian cancer cell lines indicates novel therapeutic possibilities with existing and emerging drugs

Abstract There is an urgent need to develop better understanding of the drug responsivenes in ovarian cancer (OC), particularly in the clear cell and mucinous subtypes, which tend to be resistant to the commonly used platinum-based regimens. This would help to improve survival and facilitate precision medicine approaches to therapy. In order to discover previously unsuspected anti-cancer effects with approved and emerging drugs, we applied Drug Sensitivity and Resistance Testing (DSRT) technology (Pemovska et al., Cancer Discovery, 2013) to determine detailed dose-response effects of 300 drugs in 25 established OC cell lines (10 serous, 10 clear cell and 5 mucinous ovarian cancer cell lines). The panel covered 160 approved drugs as well as 162 emerging, investigational and pre-clinical oncology compounds such as kinase and non-kinase inhibitors. All drugs were tested in 5 different concentrations covering a 10,000-fold concentration range using Labcyte nano-dispensing technology, in order to generate detailed dose-response curves for each drug in each cell line. The area under the curve was estimated from the dose-response curve to obtain the drug sensitivity score. Bioinformatic processing of the drug response data from OC cell lines resulted in several key observations. First, the DSRT data made it possible to classify OC cell lines into four functional taxonomic subtypes based on comprehensive drug responses. Interestingly, these clusters did not depend on the histological origin of the OC cell lines. Second, the 322 drugs were clustered into functional subsets based on the response data across the 25 OC cell lines. Most of this clustering followed the expected chemical similarity and target space of the drugs, such as topoisomerase II inhibitors, MEK inhibitors, mTOR inhibitors and Taxanes each clustering in their own subgroups. Third, we found that many emerging, currently not-yet-approved drugs were active in subgroups of OC cell lines, including both kinase as well as non-kinase drugs, such as HDAC inhibitors Entinostat and Belinostat. DSRT technology provides a powerful strategy for assessing drug response in OC cell models, and it could also help to asses drug responses in patient-derived ex vivo model systems of OC. Analysis of correlations of DSRT data with genomic data of the cell lines is underway and will yield new translational and pharmacogenomic opportunities for OC. Citation Format: Akira Hirasawa, Astrid Murumägi, Mariliina Arjama, Bhagwan Yadav, John Patrick Mpindi, Krister Wennerberg, Tero Aittokallio, Daisuke Aoki, Olli Kallioniemi. Systematic high-throughput drug sensitivity and resistance testing (DSRT) of ovarian cancer cell lines indicates novel therapeutic possibilities with existing and emerging drugs. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5384. doi:10.1158/1538-7445.AM2014-5384

Advances in patient-derived tumor xenografts: From target identification to predicting clinical response rates in oncology

Most oncology compounds entering clinical development have passed stringent preclinical pharmacology evaluation criteria. However, only a small fraction of experimental agents induce meaningful antitumor activities in the clinic. Low predictability of conventional preclinical pharmacology models is frequently cited as a main reason for the unusually high clinical attrition rates of therapeutic compounds in oncology. Therefore, improvement in the predictive values of preclinical efficacy models for clinical outcome holds great promise to reduce the clinical attrition rates of experimental compounds.Recent reports suggest that pharmacology studies conducted with patient derived xenograft (PDX) tumors are more predictive for clinical outcome compared to conventional, cell line derived xenograft (CDX) models, in particular when therapeutic compounds were tested at clinically relevant doses (CRDs). Moreover, the study of the most malignant cell types within tumors, the tumor initiating cells (TICs), relies on the availability of preclinical models that mimic the lineage hierarchy of cells within tumors. PDX models were shown to more closely recapitulate the heterogeneity of patient tumors and maintain the molecular, genetic, and histological complexity of human tumors during early stages of sequential passaging in mice, rendering them ideal tools to study the responses of TICs, tumor- and stromal cells to therapeutic intervention.In this commentary, we review the progress made in the development of PDX models in key areas of oncology research, including target identification and validation, tumor indication search and the development of a biomarker hypothesis that can be tested in the clinic to identify patients that will benefit most from therapeutic intervention.

Gallium compounds in nuclear medicine and oncology

An overview of the most important gallium compounds in nuclear medicine and oncology in the two last decades, with an emphasis on the last decade (especially the last 5 years), is given in this review. You can also find here some recent knowledge about 68 Ge/ 68 Ga radionuclide generator modern automated synthesis modules. Gallium has long been known to concentrate in skeletal tissue, particularly regions of bone deposition and remodeling. Elemental gallium is a potent inhibitor of bone resorption that acts to maintain or restore bone mass. There are several medically useful gallium radionuclides that have made extensive contribution in both the diagnosis and therapy of diseases. A huge variety of monofunctional and bifunctional chelators have been developed that allow the formation of stable 68 Ga(III) complexes and convenient coupling to biomolecules such as amino acids, peptides, nanoparticles, or even whole cells. Gallium pharmaceuticals can be divided into two groups according to radioactivity, i.e., radiopharmaceuticals – using radioactive Ga(III) isotopes, and conventional pharmaceuticals – using non-radioactive Ga(III) ion. The pharmaceuticals can also be divided according to the target site of a drug, i.e., those having an impact on soft tissue (most of the drugs) and hard tissue (bones and bone metastasis). In oncology and nuclear medicine, gallium and its compounds have been applied for imaging as well as therapy, and their importance in this field is still growing.

Abstract A16: A drug combination screen identifies taxanes as synergistic agents with the oral IAP inhibitor Debio 1143 in non-small cell lung cancer cells.

Abstract Background: Drug resistance is a major problem in cancer therapy. The combination of drugs targeting simultaneously multiple critical nodes of the signalling networks controlling growth and survival of cancer cells is necessary to achieve long-lasting responses. The members of the Inhibitor of apoptosis protein (IAP) family are key negative regulators of programmed cell death. Their frequent overexpression in most cancer types contributes to tumor cell survival and resistance to cancer therapy making IAPs attractive therapeutic targets. The oral monovalent SMAC mimetic, Debio 1143/AT-406, functions as an antagonist of multiple IAP proteins (cIAP1/2 and XIAP) and is currently in clinical development for cancer treatment. The goal of this study is to identify novel synergistic combination partners with Debio 1143 in non-small cell lung cancer (NSCLC). Material and Methods: An in vitro high-throughput combination screen was performed using 6 human NSCLC cell lines bearing various genetic alterations. Debio 1143 was pairwise combined with 128 commercially available oncology compounds in a cell viability assay. To identify supra-additive drug combinations, the dose-response curves were analysed using the Bliss independence method. Synergistic combinations were further studied using tumor xenograft mouse models. Results: Among several interesting combinations, we observed strong synergism of Debio 1143 combined with docetaxel or paclitaxel, two standard-of-care drugs in NSCLC. The beneficial effect of the combination between Debio 1143 and taxanes was further validated in multiple mouse cancer xenografts where the combination caused marked anti-tumour activity that was superior to either monotherapy. Conclusion: These findings underline the feasibility of using in vitro high-throughput screening for the discovery of novel drug combinations with increased anti-tumour efficacy in vivo. Furthermore, they provide a rationale for the combination of the SMAC mimetic Debio 1143 with taxanes and are the basis for ongoing clinical trials in several cancer types. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A16. Citation Format: Casey G. Langdon, Norbert Wiedemann, Mathew A. Held, James T. Platt, Frédéric Lévy, Claudio Zanna, Grégoire Vuagniaux, Mel Sorensen, Shaomeng Wang, Marcus W. Bosenberg, David F. Stern. A drug combination screen identifies taxanes as synergistic agents with the oral IAP inhibitor Debio 1143 in non-small cell lung cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A16.

Abstract C280: Oncology therapeutics show unique cardiotoxic profiles in human cardiac cells.

Abstract Tyrosine Kinase Inhibitors (TKI) have greatly improved the treatment and prognosis of multiple cancer types. However unexpected clinical cardiotoxicity has been shown with some of these agents that was not wholly predicted by current preclinical toxicity assessment methods. Since cardiotoxicity with TKI are often caused by the inhibition of signaling pathways critical to cardiac cell function, multi-targeted TKI that block multiple pathways increases the likelihood for cardiac cell damage. We recently demonstrated that an in vitro multi-parameter test panel assessing the effect of drug treatment on overall cardiac health and function could accurately predict the cardiotoxicity of 4 FDA-approved TKI. The 3 multi-targeted TKI clinically associated with severe cardiac adverse events (crizotinib, sunitinib, nilotinib) all proved to be cardiotoxic in our in vitro tests while the more targeted and relatively cardiac-safe drug erlotinib showed only minor changes in cardiac cell health. The present studies expand upon this initial observation to include other TKI, chemotherapeutic agents, and non-oncology compounds which were grouped based on their known clinical toxicity profiles ranging from cardiac safe to withdrawn. We then assessed the cardiotoxic potential of these compounds by examining their effect on cell viability, reactive oxygen species (ROS) generation, lipid formation, troponin secretion and beating activity in a human induced pluripotent-derived cardiac stem (iPS) cell model. The results showed a unique cardiotoxic signature of oncology therapeutics that was significantly different from other classes of drugs such as anti-arrhythmics. Oncology compounds induced potent cell death and lipid formation (metabolic stress) in iPS cells while anti-arrhythmics more potently disrupted cardiac cell beating with minimal impact on cell viability. In addition, troponin secretion was directly correlated with cardiac cell death for all of the oncology agents. In comparison, the cardiac-safe drugs, including non-oncology compounds and more targeted TKI, did not negatively affect any of the endpoints that assessed cardiac cell health and function. Thus different classes of drugs appear to show unique toxicity profiles that may reflect multiple mechanisms which lead to cardiotoxicity. Specifically our data suggest that more promiscuous TKI which inhibit the function of multiple oncogenic targets may be affecting pathways which are critical for cardiac cell health while more targeted agents are less cardiac toxic. These studies show that a multi-parameter approach can provide a robust characterization of drug-induced cardiac cell toxicity that can be leveraged to improve drug safety during early phase development. Furthermore, these studies emphasize the importance of developing more targeted oncology agents which are effective at killing cancer cells but lack toxic effects on cardiac cells. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C280. Citation Format: Dominique Talbert, Kimberly Doherty, Diarmuid Moran, Robert Wappell, Patricia Trusk, Scott Shell, Sarah Bacus. Oncology therapeutics show unique cardiotoxic profiles in human cardiac cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C280.

Abstract A217: Impact of pharmacokinetic (PK) variability on dose finding in phase 1 oncology studies.

Abstract Background: The key objective of Phase 1 dose escalation studies in patients for oncology compounds is to define the maximum tolerated dose (MTD) or biologically active dose range with high confidence. Small patient numbers and inter-patient heterogeneity are unavoidable factors in traditional “3+3” designs and contribute to uncertainty in MTD determination. It is hypothesized that PK variability in systemic exposures can increase uncertainty in defining the dose-toxicity (and dose-pharmacodynamics) relationship, thereby impacting the accuracy of dose finding in Ph 1. We herein performed simulations to quantitatively assess the impact of PK variability on MTD selection. Materials and Methods: Three virtual scenarios of varying steepness of the exposure-toxicity relationship and 4 scenarios of PK variability (coefficient of variation [CV]: 80% [High], 40% [Moderate], 20% [Low], 0% [None]) were considered for simulations. Dose-linear PK was assumed and a standard “3+3” escalation design was used for simulations. The hypothetical starting dose was 1 mg and dose escalations used a modified Fibonacci scheme. 10,000 simulations were performed for each of the 12 scenarios, and the frequency of each dose selected as MTD was reported. The selected MTD was defined to have 20-33% dose-limiting toxicity rate. Results: The simulation results are summarized as follows: Regardless of the dose-toxicity relationship, increases in PK variability lead to a higher likelihood of underestimation of the MTD. Selecting the correct MTD is approximately 3 - 4 times more likely with low PK variability than with high PK variability. Conclusions: Substantial PK variability can compromise the accuracy of MTD or recommended phase 2 dose determination in Ph 1/ Ph 1b dose escalation studies, emphasizing the importance of controlling PK variability in dose-finding oncology studies through optimal drug formulations and inclusion/ exclusion criteria that are customized to the predicted ADME (Absorption, Distribution, Metabolism, Excretion) properties of the development candidate. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A217. Citation Format: Xiaofei Zhou, Yi Liu, Karthik Venkatakrishnan. Impact of pharmacokinetic (PK) variability on dose finding in phase 1 oncology studies. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A217.

Abstract A34: Development of a drug sensitivity testing pipeline towards the establishment of precision medicine for ovarian cancer

Abstract Ovarian cancer (OC) has the highest mortality rate among all malignant tumors of the female genital tract. There is a pressing need for targeted drugs with better anti-cancer selectivity, particularly in patients with platinum-refractory and recurrent OC. Less than 20% of such patients respond to conventional cytotoxic chemotherapy regimens. Compared to other cancers, molecularly targeted drugs are seldom used for the treatment of any OC. Thus, there is an urgent need to develop better understanding of the drug sensitivity in OC, particularly in the clear cell and mucinous subtypes, which tend to be resistant to platinum-based regimens, in order to improve survival and to facilitate precision medicine approaches to therapy. Large-scale studies using cancer cell lines (Barretina J et al. Nature, 2012; Garnett MJ et al. Nature, 2012.) have been proposed to help in identifying links between genomic changes and drug sensitivity. While OC has been included in such studies, the number of OC cases is still small, and most samples come from the common serous subtype. In order to discover previously unsuspected anti-cancer capabilities of approved or emerging drugs, we have established a Drug Sensitivity and Resistance Testing pipeline for 280 cancer drugs (Pemovska et al., manuscript, 2013). Here, the DSRT platform was applied to analyze 25 OC cell lines and 2 cell lines from ovarian surface epithelial cells. Cell lines were plated in 384-well plates where drugs had been pre-printed using acoustic nano-dispensing technology (Labcyte®) each in five doses over a concentration range spanning 5 logs. The panel covered drugs approved by the Food and Drug Administration, European Medicine Agency, or Pharmaceuticals and Medical Devices Agency as well as emerging, investigational, and pre-clinical oncology compounds such as kinase and non-kinase inhibitors. Cell viability was measured using Cell Titer Glow® luminescence assays at 3 days. Analysis of quantitative dose-response curves using Dotmatics® software was applied to measure 50% inhibitory concentrations (IC50) values. The area under the curve was estimated from the dose-response curve of each compound and was compared across all samples to obtain the drug sensitivity score (DSS) (Yadav et al., manuscript, 2013). Bioinformatics processing of the data from OC cell lines resulted in several key observations. Importantly, we found many emerging, currently not-yet-approved drugs in several OC cell lines, including both kinase (e.g. phospho-receptor tyrosine kinases, checkpoint and mitotic kinases, Raf kinases, mitogen-activated protein kinase kinase, janus kinases, mammalian target of rapamycin, phosphoinositide 3-kinase) as well as non-kinase (e.g., histone deacetylase inhibitors, and poly (ADP-ribose) polymerase) drugs. The molecular predictors of efficacy of these drugs are being explored by correlating DSRT data with the genomics and transcriptomics data of the OC cell lines. In summary, several emerging anti-cancer drugs show potential in subsets of OC cell lines, according to data from direct testing of drug efficacy. The DSRT pipeline could be a powerful novel strategy for assessing OC drug response in OC cell models. Correlations with genomic data could yield new translational and pharmacogenomic opportunities for OC. Citation Format: Akira Hirasawa, Astrid Murumägi, Bhagwan Yadav, John Patrick Mpindi, Arjama Mariliina, Tero Aittokallio, Krister Wennerberg, Daisuke Aoki, Olli Kallioniemi. Development of a drug sensitivity testing pipeline towards the establishment of precision medicine for ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr A34.

An acute rat in vivo screening model to predict compounds that alter blood glucose and/or insulin regulation

IntroductionDrug-induced glucose dysregulation and insulin resistance have been associated with weight gain and potential induction and/or exacerbation of diabetes mellitus in the clinic suggesting they may be safety biomarkers when developing antipsychotics. Glucose and insulin have also been suggested as potential efficacy biomarkers for some oncology compounds. The objective of this study was to qualify a medium throughput rat in vivo acute Intravenous Glucose Tolerance Test (IVGTT) for predicting compounds that will induce altered blood glucose and/or insulin levels. MethodsAcute and sub-chronic studies were performed to qualify an acute IVGTT model. Double cannulated male rats (Han–Wistar and Sprague–Dawley) were administered vehicle, olanzapine, aripiprazole or other compounds at t=−44min for acute studies and at time=−44min on the last day of dosing for sub-chronic studies, treated with dextrose (time=0min; i.v.) and blood collected using an automated Culex® system for glucose and insulin analysis (time=−45, −1, 2, 10, 15, 30, 45, 60, 75, 90, 120, 150 and 180min). ResultsOlanzapine significantly increased glucose and insulin area under the curve (AUC) values while aripiprazole AUC values were similar to control, in both acute and sub-chronic studies. All atypical antipsychotics evaluated were consistent with literature references of clinical weight gain. As efficacy biomarkers, insulin AUC but not glucose AUC values were increased with a compound known to have insulin growth factor-1 (IGF-1) activity, compared to control treatment. DiscussionThese studies qualified the medium throughput acute IVGTT model to more quickly screen compounds for 1) safety — the potential to elicit glucose dysregulation and/or insulin resistance and 2) efficacy — as a surrogate for compounds affecting the glucose and/or insulin regulatory pathways. These data demonstrate that the same in vivo rat model and assays can be used to predict both clinical safety and efficacy of compounds.

Abstract 2798: Champions TumorGraft™ models represent oncology clinical trial populations.

Abstract One of the challenges in oncology drug development is the inability of traditional in vivo models to predict clinical responses. Champions Oncology overcomes this challenge through the use of its innovative Champions TumorGraft™ platform, where primary human tumors are implanted into immunocompromised mice in a manner that preserves the biological properties of the original human tumor. The current study evaluated the molecular and demographic characteristics of the Champions TumorGraft™ bank to demonstrate that these models closely resemble cancer patients that pharmaceutical companies encounter in clinical trials during the development of innovative and targeted oncology compounds. In particular, the relative frequency of ethnicity, age, and geographic location in the Champions TumorGraft™ bank closely aligns with patients enrolled in oncology clinical trials. For instance, greater than half of the models in Champions TumorGraft bank are derived from patients with advanced disease, who failed several previous lines of therapy. This is extremely important for accurate translational research, as most patients enrolling in critical mid-stage oncology clinical trials often have advanced disease and have failed multiple lines of therapy. Additionally, in recent years, clinical trials have progressed to designs where there are specific enrichments in patient populations/sub-populations based on the incorporation of companion diagnostics. Molecular evaluation of the Champions TumorGraft™ bank identifies models that possess genomic signatures or pathway expressions which can be used to identify and validate potential enrichment strategies. For example, 40% of Champions’ NSCLC models possess p53 mutations and 36% of all NSCLC clinical cases also possess p53 mutations according to the COSMIC database. Additionally, 50% of Champions colorectal TumorGraft models possess K-ras mutations, whereas 36% the clinical colorectal cancer population possesses this mutation. These cases, as well as other mutations observed across several tumor types, demonstrate that the TumorGraft mutation prevalence is representative of the prevalence in cancer patients. Together, these results demonstrate that Champions TumorGraft™ models represent a unique preclinical in vivo platform that correlate to oncology clinical trial populations. Overall, these results suggest that Champions TumorGraft™ models are capable of predicting the clinical effectiveness of drug candidates and can accelerate and enhance oncology drug development. Citation Format: Tin Oo Khor, Jay Friedman, Dhanrajan Tiruchinapalli, Nathan Anderson, David Sidransky, Elizabeth M. Bruckheimer. Champions TumorGraft™ models represent oncology clinical trial populations. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2798. doi:10.1158/1538-7445.AM2013-2798