Day 1 - Thursday February 19, 2009

7:00

Registration & Breakfast

7:55

Chairman's Opening Remarks

Session I: Challenges and Successes of Modern Cancer Drugs

[KEYNOTE PRESENTATION]

8:00

What Were We Thinking Then? What Are We Thinking Now?
Anticipating the Needs of Cancer Patients 10+ Years from Now

Approximately 10 years ago the cancer drug discovery laboratories at BMS were "thinking" about the next generation of cancer drugs and started down a path which led to the launch of Sprycel and Ixempra in successive years (2006/2007), These two anticancer agents represent polar opposites in terms of Mechanism of action (tubulin stabilization vs kinase inhibition), targeted vs cytotoxic, patient enriched vs conventional phase I development, and speed of discovery and development. The lessons learned from these experiences have continuously informed our laboratory scientists and clincial development teams. Today, we are again "thinking" about the next generation of cancer drugs, those that will be entering the market at the end of the NEXT decade! Which drug targets best fit the profile of future therapies? What will the standard of care be 5 -10 years from now? Because, the research programs we start today will go up against this future standard of care. Rational combinations of targeted agents, patient profiling, non-invasive molecular imaging, next generation biologic agents, immunotherapics, tackling "undruggable" protein-protein targets, targeting tumor stem cells and metastasis, and resistance to current anti-angiogenic agents, are all important strategies being considered today. This diversity of approaches is reflected in the current BMS Oncology portfolio of nearly 15 compounds in active development. The vigor of this portfolio is maintained by a combination of internally discovered BMS programs and a complimentary partnering strategy that integrates the speed and innovation of Biotech with the depth and breadth of Pharma. This presentation will share the lessons learned from our bench to market experiences and discuss some of our strategy for anticipating the state of cancer therapy in 2020.

8:45

Development of an RNAi Therapeutic for the Treatment of Liver Cancer

Dinah Sah, Ph.D., Vice President, Research, CNS and Oncology, Alnylam Pharmaceuticals

Malignancies of the liver, including hepatocelluar carcinoma and metastatic tumors of different origin, represent a high unmet medical need. Current therapeutic strategies frequently comprise inhibiting more than one molecular pathway contributing to tumor growth and maintenance. We are developing an RNAi therapeutic for liver malignancies comprising liposomally formulated small interfering RNAs (siRNAs) targeting VEGF and the mitotic kinesin, KSP (Eg5, Kif11). For each target, potent and specific siRNA duplexes have been identified following extensive screening in cell culture. Silencing of KSP in vitro leads to cell death in multiple tumor cell lines, while silencing of VEGF leads to inhibition of VEGF secretion into cell culture medium. To achieve hepatic delivery, lipid particle formulations have been evaluated and shown to achieve silencing of hepatic gene expression with multiple siRNAs directed against distinct targets, including VEGF and KSP. To evaluate the potential of this approach for treating liver cancer, pre-clinical orthotopic liver tumor model studies have been conducted, demonstrating mRNA reduction and cleavage consistent with an RNAi mechanism, monoaster formation consistent with KSP inhibition, prevention of tumor growth, and prolongation of survival. These studies indicate the potential therapeutic benefit of an RNAi therapeutic targeting VEGF and KSP for the treatment of liver cancer.

Session II: Cancer Drug Discovery Strategies

9:15

Targeting Protease Activities in Cancer Metastasis

Beverly Z. Packard, Ph.D., President, OncoImmunin, Inc.

Protease activities expressed by and around tumor cells remain potential targets for therapeutic intervention in cancer. This is due to the impact that clearly defined biochemical pathways specific to the interactions between migrating tumor cells and their surrounding macromolecular networks would have on our understanding of cancer metastasis. Unfortunately, despite considerable efforts in this area, fundamental questions remain. Two such questions are: (1) the dependence of metastatic tumor cells on proteolytic activities for migration through physiologic barriers such as basement membranes and underlying stroma and (2) the identification of cells producing protease molecules and activation mechanisms thereof. Moreover, since the large protease literature suggests participation of multiple protease families in the cancer metastatic process, detection of individual protease activities as well as multiple proteases with complementary or dependent activities is essential. Data from studies to be presented extend a proprietary technology developed for imaging and quantitating protease activities inside live cells to the assessment of proteolytic activities on the surfaces of tumor cells migrating through synthetic extracellular matrices (ECM) as well as those derived from cells of ECM origin, e.g., fibroblasts. Thus, utilization of this unique probe design enables simultaneous determination of individual proteases which facilitate transit of tumor cells through networks composed of single as well as ensembles of macromolecules which are natural constituents of basement membranes and stroma as well as matrices laid down by cells found in stroma.

9:45

Prevention of Ovarian Cancer Peritoneal Metastasis by Designing Blocking Strategies of CA125/Mesothelin Interaction Using Natural or Recombinant Antibodies

Nathalie Scholler, Ph.D., Assistant Professor, University of Pennsylvania

Preventing peritoneal implantation of ovarian carcinoma cells could prolong patient remission and survival. CA125, an ovarian cancer biomarker that is expressed on most ovarian cancer cells, is a ligand of mesothelin, a peritoneal protein constitutively expressed by peritoneal cells but also an ovarian cancer and mesothelioma marker. We developed a cell-adhesion model system for in vitro quantification of the binding between CA125-expresser cells and human mesothelin transfected cells. This system supplies a high-throughput screening system for reagents able to block CA125-mesothelin mediated cell attachment with a sensitive quantitative readout. Using this system, we demonstrated that a mesothelin chimeric protein and antibodies (natural or recombinant) directed against CA125 or mesothelin could block cell-mediated attachment.
To generate anti-mesothelin antibodies, we used a novel yeast-expression system to produce secreted, in vivo biotinylated recombinant antibodies called biobodies (Bbs). In vivo biotinylation of the yeast-secreted proteins is achieved by a biotin ligase produced by the yeast mating partner and directed to the yeast secreting compartment via KEX sequences. In vivo biotinylation specifically arises on a biotin accepting site (BCCP) fused to the secreted scFv, in frame with an IgA hinge in C- or N-terminal. Because the BCCP is distant from the scFv, conformational alterations during antigen-independent binding become negligible, which preserves scFv antigen-specific binding. Anti-mesothelin Bbs derived from high affinity yeast-display scFv detected both membrane-bound and soluble mesothelins and inhibited CA125/mesothelin-dependent cell attachment.

10:15

Networking and Refreshment Break

10:45

Prognostic and Predictive Markers of Today Pinpoint the Drug Targets for Tomorrow

John Martens, Ph.D., Senior Scientist, Department of Medical Oncology, Erasmus MC

Patients with breast cancer only die from their disease if they have an aggressive tumor which is therapy resistant. Our translational research focuses on the molecular characterization of clinical breast cancer with the aim to uncover risk profiles that can guide the physician in the prediction of breast cancer prognosis and of the clinical benefit of a particular systemic treatment. The publication of the sequence of the human genome and the advances in the area of genomics leading to various high-throughput genomic approaches has allowed us to identify gene expression signatures that can predict with considerable accuracy if a tumor will relapse and where, and if a tumor will respond to endocrine and/or conventional chemotherapy. Currently, we are extending this work to identifying microRNA signatures associated with the above mentioned endpoints. Combining these transcriptome data with public and in house genomic information and using bioinformatic tools such as gene set enrichment analysis and global testing has revealed that we start to mechanistically understand breast cancer aggressiveness and resistance to certain types of therapy. Understanding basic mechanisms of disease progression provide important handles to discover new targets for treatments that are more likely to be effective. In vitro generated drug sensitivity gene signatures for a wide variety of drugs further allow us to more effectively find those effective targets. Thus, prognostic/predictive signatures reveal molecular mechanisms of disease progression and this way provide a rationale for the rapid discovery of new targets for treatments which are more likely to be effective.

BENEFITS FROM THIS TALK:
- Prognostic and predictive gene and miRNA signatures for breast cancer will be presented;
- Mechanistic knowledge of breast cancer disease progression will be extracted from the identified gene signatures;
- Knowledge-based rationale for drug design will be presented;
- Potential novel drug target for breast cancer will be discussed.

11:15

Early Detection of Liver Disease and Liver Cancer in People with Newly Discovered Markers

Timothy M. Block, Ph.D., President, Hepatitis B Foundation and Professor, Drexel University

Our comparative analysis of the N-glycans on specific glycoproteins derived from the circulation of animals and people as a function of liver disease has helped identify a set of fucosylated proteins associated with fibrosis and hepatocellular carcinoma (HCC). For example, a blinded study with more than 600 patient samples, showed that circulating levels of the glycoprotein, GP73, is a substantially better correlate of a diagnosis of HCC than are the current standards AFP or L3 AFP. Moreover, levels of GP73 were reduced following tumor resection or ablation, reinforcing the hypothesis that GP73 is tumor associated. Fucosylated glycoforms of several acute phase proteins also appear to correlate with early cancer diagnosis. We have also identified a glycoform of IgG that is elevated in 100% of the more than 370 people with a diagnosis of cirrhosis, and almost everyone with stage 3 and greater fibrosis, yielding ROC values of more than 0.9, when considering negative predictions. This IgG is specific for epitopes on LPS, suggesting a role for microorganisms early in disease. Our methods are also being used to identify biomarkers of prostate and colorectal cancer, suggesting a plat form approach. These markers are expected to be useful in early disease detection, prognosis, and follow up and may even correlate with beneficial drug intervention.

11:45

Targeting Signaling Pathways in Prostate Cancer – an Evolving Approach

Liang Schweizer, Ph.D., Oncology Drug Discovery,  Bristol-Myers Squibb

Carcinoma of the prostate (CaP) is the 2nd leading cause of cancer-related deaths in men in the United States. The prostate gland is an androgen-dependent organ and thus undergoes involution upon androgen deprivation. Similarly, prostate cancers generally respond to androgen ablation, triggering programmed cell death and forming the basis for the most common therapies currently used for treatment of advanced prostate cancer. However, patients failing androgen ablation will eventually die from hormone-refractory prostate cancer. A crucial event in CaP progression is the conversion from a hormone-sensitive to a hormone-refractory disease state. Correlating with this transition, androgen receptor (AR) amplification and mutations are often observed in patients undergoing hormonal ablation therapies. It is not well understood how AR signals with low or little amounts of androgen present, although various mechanisms have been proposed to explain the role of AR in hormone-refractory CaP. One such theory is the activation of AR signaling by other growth factors or signaling pathways. Therefore, targeting AR or other growth signaling pathways is a possible approach in the treatment of hormone-refractory CaP.
This presentation:
• Illustrates current challenges of the treatment of prostate cancers
• Discusses current candidate for AR antagonist
• Introduces other possible signaling pathways involved in prostate cancer
• Explores possible approaches targeting other signaling pathways

12:15

The Cancer BioChip System

Rula Abbud-Antaki, Ph.D., President and CSO, Falcon Genomics

Recent genomic breakthroughs led to the identification of patient-specific variations in cancer genes, revealing the need for individualized cancer diagnostic testing and selection of patient-specific optimal therapies. Tumor gene expression profiles are gradually being adopted by clinicians in their diagnostic evaluation and prognostic assessment of several types of cancer. Several companies have commercially developed gene expression assays for prediction of tumor recurrence in breast cancer patients. Although these assays are capable of giving better prediction of therapeutic outcome, they do not give information about the functional contribution of abnormally expressed tumor genes to cancer cell growth, since not all abnormally expressed tumor genes can cause cancer. Cancer initiating genes will need to be targeted for individualized therapy.
The Cancer BioChip System (CBCS) is a patent-pending technology developed by Falcon Genomics, Inc. to meet the demand for a personalized cancer diagnostic and therapeutic tool. The CBCS identifies, in a high-throughput manner, genes that are required for anchorage-independent growth, a hallmark of tumor stem cells and cellular transformation. Anchorage-independent growth assays have been considered to be the gold-standard for in vitro cancer therapeutic validation. The CBCS provides a tool for high-throughput identification of silencing RNA (siRNA) that can inhibit anchorage-independent three-dimensional tumor cell growth, with minimal use of reagents and cells.

12:45

Lunch

2:15

Biomarker Approaches in the Early Development of PI3K Pathway Inhibitors

Douglas Laird, Ph.D., Director, Translational Medicine, Exelixis, Inc.

The phosphatidylinositol 3-kinase (PI3K) pathway is frequently dysregulated in cancer cells and is implicated in multiple aspects of tumor pathobiology, including growth, survival, angiogenesis, and dissemination. In particular, activating mutations in PIK3CA (the gene encoding the catalytic subunit of PI3K), and/or loss of function/deletion mutations in the PTEN tumor suppressor gene (the product of which antagonizes the activity of PI3K) have been frequently observed in a wide range of tumor types. Also, resistance to various anticancer agents (including receptor tyrosine kinase inhibitors and cytotoxic chemotherapy) has been attributed in many cases to a failure to downregulate PI3K pathway signaling. Thus, new agents targeting the PI3K pathway may have broad utility in oncology. XL147 and XL765 are small-molecule, ATP-competitive inhibitors of PI3K pathway signaling—XL147 is selective for class 1 PI3K enzymes, while XL765 is a dual inhibitor of PI3K and mTOR. Both agents exhibit potent activity against their targets in preclinical pharmacodynamic models after oral administration, and anti-tumor activity in a broad range of xenograft models. This presentation will focus on results from preclinical and early clinical studies with these agents, with emphasis on biomarker approaches to characterize on-target activity in patients.
Highlights:
• Dysregulation in PI3K pathway plays central role in cancer.
• PI3K pathway mediates tumor resistance to targeted and conventional anti-cancer agents.
• XL147 and XL765 are small-molecule, ATP-competitive inhibitors of PI3K pathway signaling.
• Data will be presented from preclinical and early clinical studies with these agents, with emphasis on biomarker approaches to characterize on-target activity in patients.

2:45

Targeting Inhibitor of Apoptosis (IAP) Proteins for Therapeutic Intervention in Tumors

Domagoj Vucic, Ph.D., Scientist: Protein Engineering, Genentech

Inhibition of apoptosis enhances the survival of cancer cells and facilitates their escape from immune surveillance and cytotoxic therapies. Inhibitor of apoptosis (IAP) protein family members are anti-apoptotic regulators that block cell death in response to diverse stimuli. IAP proteins are expressed at elevated levels in the majority of human malignancies and because they play an active role in promoting tumor maintenance they are attractive targets for developing a novel class of cancer therapeutics. We demonstrate that small-molecule IAP antagonists bind with high affinities to select baculovirus IAP repeat (BIR) domains of IAPs and disrupt critical IAP:caspase and IAP:SMAC interactions in a dose dependent manner. Binding of IAP antagonists results in dramatic induction of c IAP auto-ubiquitination activity and rapid proteasomal degradation. Besides neutralizing these anti-apoptotic proteins, the IAP antagonists actively induce cell death that is dependent on TNF signaling and de novo protein biosynthesis. Using novel generation of compounds aimed at antagonizing particular IAP proteins we demonstrate the importance of targeting broad spectrum of the IAP family members for efficient induction of apoptosis. Finally, our IAP antagonists inhibit tumor growth in vivo as single agents and in combination with a number of standard of care anti-tumor agents. Understanding the significance of protein stability and caspase/SMAC interactions for inhibition of apoptosis by IAP proteins is important for the design of potent IAP-directed compounds for treatment of malignancies in which IAP expression contributes to tumor progression and resistance to conventional chemotherapeutic agents.

3:15

Glycoengineering May be a Generalized Technology for Enhancing Protein Therapeutic Activity

Liqin Liu, Ph.D., Research Scientist, Amgen

Therapeutic proteins have revolutionized the treatment of many diseases. Several approaches have been taken to develop protein-based therapeutic drugs with certain characteristics such as greater in vivo activity and half-life, reduced injection frequency, and increased convenience. One recently used scientific research approach is that of glycoengineering. In the case of darbopoetin alfa, carbohydrates on a recombinant protein were modified with the introduction of N-linked glycosylation motifs. This and other examples of glycoengineered proteins will be discussed.

BENEFITS:
1. Understand carbohydrate modification
2. Facilitate an understanding of Phamacokinetic properties of therapeutic proteins
3. Observe the impact of (darbopoetin alfa) Aranesp to patient care
4. Determine the applicability of glycoengineering to other proteins
5. Determine a research strategy to investigate glycoenginering

Session III: Novel Compounds and Emerging Targets (part I)

3:45

Antibody Drug Conjugates for the Treatment of Npn-Hodgkin's Lymphoma

Vanitha Ramakrishnan, Ph.D., Associate Director, Genentech

4:15

Networking and Refreshment Break

4:45

Guanylate Cyclase C Agonist a New Technology Platform for GI Disorders and Colon Cancer

Kunwar Shailubhai, Ph.D. & M.B.A., CSO, Synergy Pharmaceutical Inc.

Uroguanylin (UG), Guanylin (Gn), and bacterial heat stable enterotoxin (ST) are structurally related peptides that activate common guanylate cyclase-C (GC-C) signaling molecules and, via cyclic GMP (cGMP), regulate water and ion homeostasis in a variety of tissues and organs, including the gastrointestinal (GI) tract, kidneys, lung, prostate, etc. Previously, we reported that production of UG is dramatically suppressed in human colon tumor tissues and that this deficiency might be one of the primary reasons for colon carcinogenesis. We also showed that UG inhibited proliferation and induced apoptosis in colon carcinoma cells. In addition, oral treatment with UG not only inhibited formation of polyps but also retarded their progression to adenocarcinomas in Apc+/Min mice. The cGMP pathway also mediates anti-inflammatory effects of cellular molecules such as nitric oxide and hemeoxygenase-1, and therapies that induce cGMP (phosphodiesterase-4 inhibitors) demonstrate efficacy in murine models of IBD. Accordingly, we reasoned that agonists of GC-C, when administered orally might also produce anti-inflammatory effects in murine models of colitis. Indeed, treatment with SP304 exhibited anti-inflammatory effects in TNBS- and DSS-induced colitis in mice. Importantly, the amelioration of colitis was also associated with downregulation of some of the important pro-inflammatory cytokines such as IL-4, IL-5, IL-23, and TNF. These results strongly suggest potentials of GC-C agonist as new class of drug candidates for GI inflammatory diseases and colon cancer. Our recent data also suggest that GC-C agonists might also be useful for treatment of chronic constipation and for irritable bowel syndrome (IBS). The seminar will cover 1) Functions of GC-C agonists in GI physiology; 2) Cyclic GMP mediated signaling pathways and their roles in anti-cancer and anti-inflammatory activities; 3) Mechanism of action of GC-C agonists in GI disorders and colon cancer; and 4) Data from ongoing clinical evaluation of a few GC-C agonists will also be discussed.

5:15

The cGMP-Dependent Protein Kinases as Targets for Cancer Prevention and Treatment

Darren D. Browning, Ph.D., Associate Professor and Graduate Program Director, Medical College of Georgia

The manipulation of cellular cGMP levels by guanylate cyclase activators and phosphodiesterase inhibitors has proven to have significant therapeutic value. Several laboratories have described anti-proliferative or proapoptotic effects of cGMP signaling in colon cancer cells but the mechanism is not understood. The cGMP dependent protein kinases (PKG) are central effectors of cGMP elevating agents and are likely to mediate many of the anti-tumor effects of this pathway. Type 1 PKG expression is reduced in many tumors, and when ectopically expressed it causes reduced tumor growth in colon cancer xenografts. This anti-tumor effect of PKG is due in part to attenuated angiogenesis caused by reduced VEGF production by the cancer cells. The ability of PKG to regulate ?-catenin function in colon cancer lines implicates this pathway as central to the anti-tumor effects. These findings highlight PKG activation as an important downstream mediator of cGMP manipulation in the normal and diseased intestine.

Benefits:
• Understand the anti-tumor effects of PKG in the intestine
• Novel PKG signaling in colon cancer cells and related biomarkers will be presented
• Therapeutic considerations involving PKG activation will be discussed

5:45

Dual Targeting of the RON and c-Met Oncogenes with a Novel Small Molecule Kinase Inhibitor

Isabelle Dussault, Ph.D., Director of Research, Amgen

RON and c-Met are receptor tyrosine kinases that regulate cell proliferation, migration and invasion and that are commonly deregulated in cancer. Receptor over-expression has been most frequently described, but other mechanisms can lead to the oncogenic activation of RON and c-Met. They include activating mutations or gene amplification for c-Met and constitutively active splicing variants for RON. Aberrant activation of these kinases in human cancer suggests that they play an important role in tumor growth and makes them attractive targets for novel anti-cancer drugs. We identified a novel inhibitor of RON and c-Met, Compound I, that selectively and potently inhibited their kinase activity with IC50s of 9 nM and 4 nM, respectively. Compound I inhibited HGF- and MSP-mediated signaling and cell migration in a dose-dependent manner. Compound I was tested in vivo in xenograft models that were either dependent on c-Met or that expressed a constitutively active form of RON (RON?160 in HT-29). Compound I caused complete tumor growth inhibition in NIH3T3 TPR-Met and U-87 MG xenografts, but showed only partial inhibition in HT-29 xenografts. The effect of Compound I in HT-29 xenografts is consistent with the expression of the activating b-Raf V600E mutation which activates the MAPK pathway downstream of RON. Importantly, tumor growth inhibition correlated with the inhibition of c-Met- and RON-dependent signaling in tumors. Taken together, our results suggest that a small molecule dual inhibitor of RON/c-Met inhibits tumor growth and could therefore be useful for the treatment of patients with cancers where RON and/or c-Met are activated.
Highlights:
- Novel molecule
- Novel target – RON
- Molecule that targets 2 oncogenes that use different mechanisms to drive tumor growth
- Inform scientific community of novel findings

6:15

Poster Session & Networking Reception

Day 2 - Friday February 20, 2009

Top of the page

7:00

Continental Breakfast

7:55

Chairman's Review of Day One

[KEYNOTE PRESENTATION]

8:00

Amgen Oncology: A Comprehensive Approach to Research and Development

At Amgen there are four key principles that drive our research. We aim to (i) focus on grievous disease and unmet medical need; (ii) pick the best targets and then define whatever is the most appropriate modality, rather than being constrained to a particular therapeutic approach (“multi-modality approach”); (iii) move quickly to study the disease in people, rather than generating a multiplicity of animal models. Finally, under-pinning this is a deliberate strategy and commitment to ensure an integrated, coordinated effort from Research through to Marketing, that will bring forward the best therapeutics for patients, and as quickly as possible.
There is no area where these principles are better exemplified, or more appropriate than in Amgen Hematology/ Oncology, where our goal is to develop therapeutics that will have a meaningful impact on the lives of patients.
The programs that are currently in oncology clinical development reflect our “multi-modality approach.” They include small molecules, antibodies, peptibodies and protein ligands. These molecules represent targeted supportive care agents, or are targeting elements in the tumor stroma, or are targeting the tumor cells themselves.
Our approach to target selection is coupled with a commitment to developing biomarkers which are being used to aid in patient selection and monitor responses to therapy.
This presentation will highlight several programs that illustrate these themes.

Session IV: Novel Compounds and Emerging Targets (part II)

8:45

ABT-888, a Novel PARP Inhibitor for Treatment of Cancer

Xuesong Liu, Ph.D., Principle Investigator, Abbott Laboratories

Many established cancer therapies involve DNA-damaging chemotherapy or radiotherapy. The DNA repair capacity of the tumor represents a common mechanism used by cancer cells to survive DNA-damaging therapy. Poly (ADP-ribose) polymerase (PARP) is a nuclear enzyme that is activated by DNA-damage and plays critical roles in DNA repair. Thus inhibition of PARP represents one of the approaches to sensitize cancer cells to DNA-damaging chemotherapy or radiotherapy. We have developed a potent and selective PARP inhibitor ABT-888. ABT-888 potentiates DNA-damaging agents in vitro and in preclinical tumor models. We have also developed a biomarker assay which is useful to guide the selection of an optimal biological dose in the clinic. In addition, we will present data on the novel mechanism of action for ABT-888 to potentate damaging agents in cancer cells.
Attendees will learn:
• A novel benzimidazole class of PARP inhibitor, ABT-888
• Characterization of ABT-888 in vitro and in vivo.
• A biomarker assay to guide the selection of an optimal biological dose in the clinic
• A novel mechanism of action for ABT-888 to potentate damaging agents in cancer cells

9:15

BAL27862 – A New Tubulin-Binding Drug with a Unique Mode of Action

Heidi Lane Ph.D., Head of Cancer Biology, Basilea Pharmaceutica International AG

BAL27862 is a new tubulin-interacting agent with an apparently novel mechanism of action. A broad antitumor activity, also in drug resistant tumor models, and a potential as a vascular disruption agent strongly support development of BAL27862 as a novel anticancer agent with a potential for both i.v. as well as p.o. administration.
Key learnings:
• Not all tubulin binders exert the same phenotype
• There is a hierarchy in tubulin interaction
• Vascular disruption adds to a beneficial therapeutic index
• Taxane resitance extends beyond Pgp efflux and is addressable

9:45

Networking an Refreshment Break

10:15

Template-Directed-Assembly of RTK TK Domains Restores Biologically-Relevant Function

Edward Esposito, Ph.D., Chief Scientist, P.A. Technologies

Receptor tyrosine kinases and other membrane associated kinases are important targets in drug discovery. Use of recombinant kinase domains, from targets which are normally membrane-associated, in early stage HTS efforts often provide unreliable results including false positives, missed leads, and poor selectivity data (IGF-1R, TrkB, Tie2, and ErbB4, as examples). Because these target proteins normally reside on the cell membrane and utilize the membrane as a scaffold for assembly of complex signaling networks, we have developed a simple, homogenous, in vitro self assembly approach to create more meaningful assays. Our template-directed self-assembly approach promotes the assembly of functioning protein complexes on soluble nanometer scale template, so that the recombinant fragments function more like they do inside the cell. Our results indicate that these proteins are more active, more faithfully represent their cellular function, and have altered substrate selectivity when properly assembled, and therefore provide more meaningful results to the HTS community.
Attendees will benefit from:
1. Introduction of novel technology – not simply a new detection method
2. Solving a problem for HTS assay development groups
3. Increased signal from difficult or poorly active recombinant targets
4. Opportunity to assemble key oncogenic pathway components from purified reagents in a simple in vitro format
5. Biological relevance

10:45

Therapeutic Potential for a Specific Inhibitor of ADAM10

Marcia Moss, Ph.D., Co-Founder, BioZyme Inc.

Enzymes of the ADAM family (a disintegrin and metalloproteinase) have prodomains that can act as intra and intermolecular inhibitors of specific members, maintaining them in a latent state. For ADAM10, its prodomain, once removed, is a selective inhibitor of ADAM10 catalytic activity in both enzyme and cell based assays. Prodomain inhibits betacellulin, CD44, and HER2 shedding, suggesting that it could be used as a potential therapeutic agent for cancer. In addition, a proteomics approach that compares shed membrane proteins in the presence and absence of prodomain in BT474 cells, was used to identify novel substrates and confirm others for ADAM10 that are involved in tumor proliferation. Many of these factors are involved in signaling via the ErbB pathway while some are necessary for angiogenesis. Because prodomain inhibits the release of proteins known to promote breast cancer, we have tested its ability to work in BT474 proliferation assays. Prodomain works alone and in combination with cancer drugs that target the ErbB pathway in the BT474 cell line. Prodomain is also effective as a stand alone agent in several cell types, indicating that it has potential as a novel treatment for a variety of cancers.
Benefits:
• The question, “Should specific inhibitors of ADAM10 be used as cancer therapeutics?” will be addressed
• Defining the mechanism(s) of how ADAM10 inhibitors prevent tumor proliferation
• The use of prodomains as drugs: Answers that address the good, bad, and the ugly
• Prodomain of ADAM10 as a therapeutic agent

[Oral Presentations from Exemplary Abstracts]

11:15

Deubiquitylases as Novel Anti-Cancer Targets: Discovery and Characterization of Novel USP7 Inhibitors

Craig A. Leach, Ph.D., Senior Scientist, Progenra, Inc.

The ubiquitin-proteasome is a complex system consisting of enzymes that conjugate and deconjugate ubiquitin from target proteins. The conjugation of ubiquitin functions to regulate the intracellular activity of target proteins by altering their stability, localization and activity. Importantly, the mechanistic aspects of the ubiquitylation pathway are now being elucidated and it's now recognized that ubiquitin deconjugation is performed by deubiquitylating enzymes DUBs. The therapeutic validation of the ubiquitin-proteasome system was provided by the marketing approval of bortezomib velcade®/ PS-341 for the treatment of multiple myeloma. However, clinical trials revealed that the efficacy of bortezomib is limited by toxicities suggesting a need for novel targeted chemotherapeutic agents. In our search for novel MM chemotherapeutic agents, we investigated the therapeutic potential of inhibiting another component of the ubiquitin-proteasome pathway, the DUB, USP7. Our rationale for targeting USP7 is as follows: 1 Blockade of USP7 using siRNA or homologous recombination results in elevated levels of the tumor suppressor, p53 and cell cycle arrest in cancer cells. In contrast to the situation in the majority of human tumors, mutations or deletions of p53 in MM are relatively rare and thus the activation of p53 is likely to offer a therapeutic benefit in MM. 2 Knockdown of USP7 prevents rapid inactivation of the anti-proliferative transcription factor, FOXO4, potentially providing a mechanism to impair the pro survival PI3-kinase pathway that is commonly activated in MM. 3 A recent proteomics study using USP7 knockdown cells demonstrated that USP7 was involved in regulating numerous pathways such as DNA replication and endosomal organization. Importantly, knockdown of USP7 was not associated with any global changes in the cellular ubiquitylation status, suggesting that USP7 inhibition will have a reduced potential for toxic side effects. Progenra utilized its proprietary high throughput screening technology to screen compound collections for inhibitors of USP7. Data will be presented that describe the initial discovery and characterization of USP7 inhibitors. Specifically, one compound, P005901, specifically inhibits USP7 in vitro. In addition, P005091 inhibits the growth of human tumor cell lines but not normal cells and synergizes with FDA approved chemotherapeutic agents. Currently, P005091 is being optimized by medicinal chemistry.

11:30

Can Tumors "configure" Their Own Immune System? Cytokine Production by Malignant Tumors as an Example of Tumor Mediated Immune Constructs

Richard H. Siderits, M.D., Assistant Professor, Robert Wood Johnson  University

We describe a novel observation regarding the uniform nature of the inflammatory infiltrate in a subset of malignancies. These tumors behave in a manner best understood as "creating their own immune system". This unusual perspective refutes the polemic that cancers only evoke an immune or "inflammatory" response. Selected malignant tumors produce short acting local transients that function as cytokines or interleukins. These tumors have uniquely homogenous populations of leukocytes and the inflammatory cells show signs of cellular activation without tumor cell destruction. A phenomenon best viewed metabolically as "invitation, activation, stasis". This population of leukocytes functions in a way that is similar to the tumor having developed it's own immune construct which neither promotes nor hinders tumor growth kinetics and will likely respond to other molecular signals which the host's non co-opted immune system might respond. Tumors with solely eosinophil and plasma cell infiltrate suggest tumor cell Eotaxin production. We show specific immunohistochemical staining for Eotaxin in one such illustrative malignancy. Novel treatment options based on this unique perspective would involve the induction of gene expression for these local tumor chemokine like transients and would provide a "collateral target" for antibody mediated immunotoxin or radiotoxin delivery. Unlike a mechanism that might promote tumor growth, the induction of these transients would non-poietic in that the tumor cell cycle growth kinetics remain essentially unchanged. We propose the evaluation of substances such as Tumor Necrosis Factor or Urushiol as inducers for CCL11 gene expression for these and other tumor associated cytokine like transients.

11:45

Luncheon

Session V: Combination Therapies for Cancer Treatment

12:45

Cancer Vaccines: Moving Beyond Current Paradigms for Clinical Trial Design and Combination Therapies

Jeffrey Schlom, Ph.D., Chief, Laboratory of Tumor Immunology and Biology, Center for Cancer Research, NCI, NIH

Data are emerging from recent clinical trials involving several different cancer vaccines contrasting “tumor response” (Response Evaluation Criteria in Solid Tumors) criteria with “patient response” in the manifestation of increased patient survival post-vaccine therapy.
• There are several strategies in which cancer vaccines can be exploited in combination with other therapeutic modalities which are quite unique, when compared with “conventional” combination therapies.
• Several clinical studies with recombinant poxvirus vaccines have shown evidence of clinical benefit, most importantly, increased survival.

1:15

Specific Delivery of Multiple Therapeutic Molecules to Cancer Cells Using RNA Nanotechnology and phi29 Motor Components

Peixuan Guo, M.D., Director of Nanobiomedical Center, University of Cincinnati

We demonstrated that pRNA, a component of phi29 DNA-packaging motor, can be used as a building block for bottom-up assembly in nanotechnology. The pRNA's structural versatility, coupled with its ability to form dimers, trimers, hexamers and patterned superstructures via the interaction of two interlocking loops, makes it a promising tool for nanomachine fabrication and gene delivery.
The polyvalent pRNA complex can deliver up to six kinds of therapeutics to specific cancer cells, as demonstrated in breast cancer, leukemia, lung cancer and prostate cancer cell lines. Incubation of the RNA nanoparticles containing receptor-binding aptamer or folate resulted in cell binding and transporting the chimeric pRNA/siRNA, pRNA/ribozyme or drugs into cells, subsequently modulating programmed cell death. Specificity was brought about by the inclusion of a subunit in the complex to include cell receptor binding ligands for receptor mediated endocytosis, and RNA aptamers that bound to specific cell surface markers. The efficiency was confirmed in animal trials. RNA chemical modification was applied to generate stable RNA nanoparticles with low toxicity and to make the chimeric RNA complexes processed into siRNA by Dicer after delivery.
Using such protein-free nanoparticles, which will not induce the production of antibodies, as therapeutic reagents would allow for long-term administration to avoid the immune response due to repeated treatment for the diseases.
Benefits:
1. The use of such 20-40 nm motor pRNA/siRNA complex could extend the half life of the therapeutic molecules in vivo to avoid the short retention time of small molecules. And avoid the problem of undeliverbility due to the size larger than 100 nm.
2. The motor pRNA can deliver siRNA, ribozyme or other therapeutic molecules to specific cells and modulate programmed cell death. The specificity can be achieved by conjugate folate or RNA aptamers, which can target to cancer cells.
3. The polyvalent pRNA can deliver up to six kinds of therapeutic molecules and target delivery molecules.
4. Such protein-free, stable and low toxic RNA complex could avoid the problem of inducing antibodies in vivo so that can be used for repeated treatment of disease.

1:45

Novel Selective and Synergistic Multiple Myeloma Targets Discovered through Systematic Combination Screening

Richard Rickles, Ph.D., Director, Oncology, CombinatoRx

High throughput combination screening (cHTS) allows the systematic testing of combinations of approved drugs and other biologically active molecules in cell-based assays of tumor cell proliferation and viability. In this approach we generate a concentration matrix for each chemical combination, capturing the combined activity of two compounds over a broad range of single agent concentrations. Quantitative scoring of concentration response matrices using models of drug interactions allows insight into the biological mechanism of action of drug combinations and the discovery of novel therapeutic applications. Using cHTS, we have discovered that agonists of either adenosine A2A receptors (A2A) or beta-2 adrenergic receptors (bAR) demonstrate significant selective, synergistic, anti-proliferative effects in preclinical Multiple Myeloma (MM) models. The use of molecular and chemical genetics confirms these two proteins as targets. Potent, highly synergistic, inhibition of proliferation was demonstrated with combinations of A2A or bAR agonists and multiple agents including dexamethasone, lenalidomide, bortezomib, melphalan, doxorubicin, HDAC inhibitors and HSP90 inhibitors at clinically relevant concentrations. Synergistic anti-proliferative effects were observed broadly across several MM cell lines and some cell lines unresponsive to standard MM drugs. The activity, synergy and selectivity of A2A and bAR combinations were also observed in xenograft models of MM and ex vivo with patient samples. In summary, cHTS screening has been used to discover new synergistic multi-target mechanisms and prioritize synergistic anti-proliferative combinations for preclinical evaluation.

2:15

Potentiating Anti-Cancer Immune Therapy: Selective Elimination of Immunosuppressive Regulatory T cells

Daniel Powell Jr., Ph.D., Research Assistant Professor, Deputy Director Cell & Vaccine Production Facility, University of Pennsylvania

WCD25+ FOXP3+ CD4 T regulatory (Treg) cells regulate peripheral self tolerance and possess the ability to suppress antitumor responses, implying their role in the poor clinical response of cancer patients undergoing active immunization protocols. This provides the rationale for neutralizing Treg cells in vivo to strengthen local antitumor immune responses.
LMB-2 is a recombinant immunotoxin that is the fusion a single chain Fv fragment of the anti-Tac, anti-CD25 monoclonal antibody to a truncated form of the bacterial Pseudomonas exotoxin A. We have conducted preclinical and clinical assessment of LMB-2 as an agent for selective Treg elimination. In in vitro study, incubation of human PBMC with LMB-2 selectively reduces the levels of CD4+CD25+, FOXP3 expressing cells without impairing the function of the remaining lymphocytes. The 3-hour in vivo half-life of LMB-2 makes it an attractive candidate for reducing human CD25+CD4+ Treg cells in vivo prior to the administration of cancer vaccines.
Patients with metastatic melanoma were treated with 3 doses of LMB-2 followed by peptide vaccination. Toxicities associated with LMB-2 administration were mild to moderate, with rare grade III events. LMB-2 administration resulted in a preferential, transient and partial reduction in CD25+ FOXP3+ CD4 T cells in the peripheral blood. Immunohistochemical analysis of biopsied lesions revealed a reduction in the frequency of FOXP3+ CD4+ Treg cells in the tumor as well. Despite transient systemic reduction in Treg cells, no patient developed overt autoimmunity. Augmented immune responses to cancer vaccines in vivo were not detected.
This demonstrates the capacity of a CD25-directed immunotoxin to selectively mediate a transient reduction in Treg cells in vivo. The ability to manipulate the immunoregulatory milieu of the tumor microenvironment holds significant promise for the development of powerful new immunotherapeutic strategies. The power and limitations of the CD25-directed approach to immunomodulation for cancer therapy will be discussed.

2:45

Networking an Refreshment Break

Session VI: Cancer Drugs in Clinical Trials

3:15

Novel Multi-Epitope Therapeutic Vaccine for Ovarian and Breast Cancer

Ramila Philip, Ph.D.,  President and Chief Scientific Officer, Immunotope, Inc.

Elimination of cancer through early detection and treatment to prevent recurrence is the ultimate goal of cancer research, and is especially critical for ovarian and other forms of cancers typically diagnosed at very late stages and that have very poor response rates. Proteomics has opened new avenues for the discovery of diagnostic and therapeutic targets. Immunoproteomics, which defines the subset of proteins involved in the immune response, holds considerable promise for providing a better understanding of the early stage immune response to cancer as well as important insights into antigens that may be suitable for immunotherapy. Early administration of immunotherapeutic vaccines can potentially have profound effects on prevention of metastasis and may potentially cure through efficient and complete tumor elimination. We developed a mass-spectrometry-based method to identify autoantigens that are processed and presented by MHC class I molecules on the surfaces of ovarian cancer cells. These autoantigens were highly representative of families of proteins with roles in key processes in carcinogenesis and metastasis, such as cell cycle regulation, cell proliferation, apoptosis, tumor suppression and cell adhesion. Selected MHC class I presented epitopes originated from these autoantigens were fully characterized to demonstrate CTL activity against ovarian and breast cancer cells prior to be included in a phase I clinical study. A therapeutic vaccine consists of a mixture of 12 peptides is being tested in a phase I clinical trial in high risk ovarian and breast cancer patients for safety and T cell immune response. Preliminary data from the low dose cohort of patients suggest that this multi-epitope vaccine is safe and induces individual epitope specific T cell response in immunized patients.

3:45

Targeting Cancer by Treatment with Elesclomol, a Novel Oxidative Stress Inducer

Yumiko Wada, Ph.D., Senior Director, Synta Pharmaceuticals

Cancer cells operate at high levels of reactive oxygen species (ROS) and oxidative stress. Elesclomol is a first-in-class compound that act by further increasing the level of oxidative stress in cancer cells beyond sustainable levels, inducing apoptosis. This oxidative stress induction is a novel strategy for selectively targeting and killing cancer cells. In preclinical models elesclomol showed potent anti-cancer activity, as well as an ability to enhance the efficacy of certain chemotherapy agents with minimal additional toxicity. In a recent 21-center, double-blind, randomized, controlled Phase 2b clinical trial in 81 patients with stage IV metastatic melanoma, elesclomol in combination with paclitaxel doubled the median time patients survived without their disease progressing compared to paclitaxel alone. Elesclomol has received Fast Track and Orphan drug designations from the FDA for development in metastatic melanoma. Elesclomol is currently enrolling patients in a global, pivotal, Phase III clinical trial in metastatic melanoma.
Benefits of Attending:
• Introduces elesclomol, a novel small molecule that rapidly induces ROS in cancer cells, leading to cancer cell death by apoptosis
• Discusses the novel therapeutic approach for obtaining high selectivity in killing cancer cells with minimal effect on normal cells, leading to a high therapeutic index in vivo, by exploiting a fundamental difference between cancer cells and normal cells
• Presents preclinical in vivo studies
• Presents data from a double-blinded, randomized, controlled Phase 2b trial in stage IV metastatic melanoma
• Presents design of a confirmatory Phase 3 melanoma trial under an SPA

4:15

Inhibition of Hsp90 as an Effective Alternative Mechanism to Silence Oncogenic Tyrosine Kinases: From Preclinical Studies to Phase III

Christian Fritz, Ph.D., Senior Director, Cancer Biology, Infinity Pharmaceuticals

In a growing number of cancers, deregulated signaling pathways activated by mutated or amplified tyrosine kinase receptors have been recognized as essential drivers of the disease. In some of these cancers (e.g. GIST, CML, NSCLC), specific inhibitors of the kinase activity of the transmembrane receptors have shown encouraging efficacy in the clinic. However, secondary site resistance mutations often arise in the genes of the targeted proteins, rendering the kinase inhibitors ineffective. Here, an alternative strategy is proposed. Heat shock protein 90 (Hsp90) is a protein chaperone responsible for the proper folding, function, and stability of various ‘client’ proteins. Many of the above mentioned oncogenic tyrosine kinases are ‘client’ proteins of Hsp90, i.e. their stability and function depends on Hsp90, and inhibition of Hsp90 will lead to degradation of the proteins through the ubiquitin-proteasome pathway. This degradation is independent of the mutation status of the protein. IPI-504 (retaspimycin hydrochloride) is a novel, potent, and water-soluble Hsp90 inhibitor being developed by Infinity Pharmaceuticals. In preclinical experiments, IPI-504 has demonstrated activity in multiple primary and resistant models of GIST, CML and NSCLC. IPI-504 is currently being tested in several clinical trials. Notably, encouraging results in a phase I, open label, dose escalation study in GIST patients with imatinib and sunitinib-resistant, metastatic tumors have led us to initiate a placebo-controlled, Phase III pivotal trial in GIST.
Key benefits:
• Introduction to Hsp90 as a target for cancer therapy
• Introduction to IPI-504, a novel, potent Hsp90 inhibitor
• Preclinical examples of IPI-504 efficacy in GIST, CML, NSCLC and breast cancer
• Clinical results of IPI-504 in GIST
• Development path for IPI-504 from phase I directly to a phase III pivotal trial in GIST

4:45

Conference Concludes