Grant: 6553-18 | Translational Research Program (TRP):
Location:IRIC - Institut de Recherche en Immunovirologie et en Cancerologie, Montreal, Quebec H3C 3J7
Project Title: RUNX1 Mutations That Confer Exquisite Sensitivity To GlucocorticoidsProject Summary:
Acute myeloid leukemia (AML) is a disease caused by several genetic alterations, including mutations in the RUNX1 gene. The presence of RUNX1 mutations in AML cells is generally associated with bad prognosis for these AML patients, and RUNX1 mutations are also the cause of Family platelet disorder, which predisposes these patients to AML development. In order to discover novel cures for patients suffering from RUNX1-mutated AML, we identified glucocorticoids as effective drugs that kill AML cells carrying RUNX1 mutations. In this proposal, we plan to perform experiments to better understand how these molecules kill these AML cells and test the ability of GCs to cure mice that we will engineer to develop AMLs harboring RUNX1 mutations, in the hope of bringing this discovery to the clinic to improve treatment of patients suffering from RUNX1- mutated AML.
Grant: 5471-18 | Career Development Program (CDP):
Location:Harvard Medical School, Boston, Massachusetts 02241-5649
Project Title: Studying The Function Of Co-activator MAML1 In Notch-associated T-cell Acute Lymphoblastic LeukemiaProject Summary:
Normal cell growth and differentiation relies on a small number of signaling pathways that direct the gene expression patterns unique to each cell type. One pathway particularly important in cell-cell communication is the Notch pathway, which normally relies on direct contact between a signal-sending cell and a signal-receiving cell. After the signal is activated, a portion of the Notch protein enters the cell nucleus and forms a complex with two other proteins, called RBPJ and MAML1, to regulate the expression of genes that control cell growth and cell fate decisions. Aberrant activation of the Notch pathway by mutations, however, leads to the development of T cell acute lymphoblastic leukemia (T-ALL). In fact, Notch1 mutations are found in more than half of all human T-ALL cases. The goal of my project is to understand how the MAML1 gene cooperates with Notch to induce the production of Notch-responsive genes. In one line of study, I will use a Notch inhibitor to toggle the Notch pathway between “on” and “off” states, and determine what protein partners MAML1 chooses in the “Notch active” state and how these partnerships affect its function. I will also analyze the temporal sequence of events that take place in the nucleus after Notch is switched on in leukemic cells, focusing on the role of MAML1 in the induction of target gene expression. These studies will help us understand how Notch and MAML1 cooperate to stimulate aberrant gene expression in leukemic cells and may lead to new strategies for therapeutic development in T-ALL.
Grant: 1348-18 | Career Development Program (CDP):
Location:Northwestern University, Evanston, Illinois 60208
Project Title: The Role Of Plek2 In The Pathogenesis Of Myeloproliferative NeoplasmsProject Summary:
Myeloproliferative neoplasms (MPNs) are a group of bone marrow diseases with overproduction of mature blood cells and increased risk of evolving to acute leukemia. A specific mutation on one of the blood cell surface proteins called Jak2 is the leading cause of this group of diseases. The discovery of this mutation led to the development of inhibitors specifically targeting Jak2. However, these inhibitors are not curative. In addition, MPN patients treated with these inhibitors often develop drug resistance and significant side effects due to the indispensable roles of this blood surface protein in normal blood production. We have been studying new approaches to treating MPNs, especially focusing on the proteins that are important for the development of MPN disease but not essential for normal blood cells. We identified one of these proteins, Plek2, which a part of normal red blood cell development but may also be involved in the disease state in some MPNs. Our studies using mouse models and tumor cell lines demonstrated that Plek2 is critical for the MPN disease development and is a mediator of Jak2 signaling. In addition,mice that lose Plek2 do not exhibit obvious side effects. These novel discoveries made Plek2 an attractive drug target for the treatment of MPNs. The overall goal of my research is to better understand how Plek2 reverts the disease progression in MPNs using mouse models and bone marrow cells from MPN patients. We will analyze how Plek2 mediates Jak2 signaling as well as how Plek2 may be involved in other MPN mutations, such as CALR and MPL. Successful completion of this project will lay the foundation for targeting Plek2 as a novel therapeutic approach for the clinical management of MPNs.
Grant: 3375-18 | Career Development Program (CDP):
Location:Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024
Project Title: Enhancing Adoptive Immunotherapy Of AML With Engineered T Cells By Expressing Immunomodulatory Fusion Proteins That Overcome Inhibitory SignalsProject Summary:
Acute myeloid leukemia (AML) is the most common acute leukemia in adults and has the worst survival rate of all leukemias, with only 26% of AML patients surviving 5 years. Since our immune cells can have the ability to eradicate tumors, immunotherapeutic approaches are being developed as treatment options with the goals of providing better efficacy and fewer side effects. One form of immunotherapy is adoptive immunotherapy, which provides an opportunity to genetically modify T cells to recognize and destroy tumors and generate a population of memory cells that can serve as a “living drug.” We identified a T cell receptor (TCR) that recognizes and tightly binds WT1 – a well-validated protein that promotes the cancerous activity of tumors – and observed clinical activity in patients with T cells modified to express this TCR. However, tumor cells can express inhibitory proteins that block activation of the T cells that recognize the tumor and thereby avoid immune-mediated eradication. To overcome this inhibition and further enhance efficacy, we engineered immunomodulatory fusion proteins (IFPs)that combine a tumor-specific inhibitory receptor with a costimulatory signaling domain, essentially to replace a “brake” with an “accelerator” for the immune response. By this method, we have effectively targeted several inhibitory proteins, demonstrated that we can significantly improve T cell therapy in a mouse model of AML, and acquired initial evidence of function in human T cells. To obtain data needed to translate our findings into the clinic, we plan to assess safety and potential toxicity to normal tissues in mouse models with T cells expressing different IFPs targeting AML cells expressing the relevant proteins. We will also assess efficacy with human IFPs in human T cells targeting AML cells in mouse models. Our long-term goals are to validate this approach in clinical trials, advancing a novel, safe and effective T cell immunotherapy that ultimately will improve AML patient outcomes.
Grant: 8012-18 | Screen to Lead Program (SLP):
Location:H. Lee Moffitt Cancer Center & Research Institute, Atlanta, Georgia 30374-2801
Project Title: Rationally Designed Dual BRD4-Kinase Inhibitors For The Treatment Of Myeloid CancerProject Summary:
Current anti-cancer targeted drugs often fail due to ineffectiveness or drug resistance, suggesting alternative strategies are needed to develop effective therapies. We recently determined that certain drugs bind to and inhibit two different classes of proteins that play important roles in cancer. These two classes are called kinases and BET proteins, which have completely different functions in the cell. The general approach in drug discovery has been to optimize a single drug to target a single protein. Our identification of the dual inhibitory activity of BET-kinase inhibitors provides an opportunity to optimize inhibiting both targets with a single drug. To this end, we have developed drugs that exhibit improved kinase and BET inhibitor activity. The ability of these compounds to target multiple regulators of cancer may provide superior effectiveness against blood cancers that are known to require both targets of the drug. For example, one of the dual inhibitors targets the JAK2 kinase, which is a major driver of myeloid cancers. JAK2 kinase inhibitors, which have been designed to solely target kinase activity, have not been successful in patients due to ineffectiveness and drug resistance. As these cancer cells also require BET protein function, our dual inhibitors may improve effectiveness and prevent drug resistance, a concept support by our initial studies. This proposal is written to support our optimization and development of our lead compounds for blood cancers.
Grant: 5474-18 | Career Development Program (CDP):
Location:The University of Chicago, Chicago, Illinois 60637
Project Title: Transcriptional And Epigenetic Roles For β-catenin In The Genomic Instability And Oncogenic Transformation Of T-cell Leukemia/lymphomaProject Summary:
Cancer arises from changes in DNA, and these changes can come in various forms. In the case of leukemia and lymphoma, most have genomic instability, meaning the normal organization of DNA (the genome) is disrupted due to improper repairing of DNA breaks. DNA is organized into structures known as chromosomes, and changes to normal chromosomal structure is evidence of genomic instability in a cell. Chromosomal defects mark approximately 80% of T-cell leukemia and often involve the moving of cancer-causing genes to other chromosomes (translocation) into positions that switch them “on.” This instability of the genome is a continuous process and allows for selection of ever more aggressive and therapy-resistant tumor cells. Our protein of interest, beta-catenin, has very tightly controlled, low expression levels in normal cells; however, uncontrolled beta-catenin expression has been linked to genomic instability in cancer through mechanisms that remain unclear.
Previous work from our lab showed that uncontrolled beta-catenin expression causes mice to develop T-cell leukemia. These leukemias have genomic instability and chromosomal defects similar to those seen in T-ALL patients. The pattern of DNA breaks suggests that the excess beta-catenin impairs mechanisms (known as checkpoints) that ensure that DNA is replicated and repaired correctly. In fact, these mice have lower than normal expression levels of genes required for DNA checkpoints and repair. Based on observations of this model, I hypothesize that beta-catenin affects multiple levels of gene regulation to impair DNA checkpoints and repair. Beta-catenin controls transcriptional mechanisms of gene expression, which switch genes “on” or “off,” as well as epigenetic mechanisms, which change the shape of DNA to allow various kinds of gene regulators to interact. Using state-of-the-art genomic technologies, I will examine DNA checkpoint and repair mechanisms to understand both transcriptional and epigenetic changes that happen in cells with uncontrolled beta-catenin. I will also examine cells from leukemia patients to apply what I see in my mouse model to human disease.
Chromosomal defects are a driving force in cancer and reflect a fundamental failure of the checkpoints that maintain genome integrity. My goal is to increase our understanding of how beta-catenin controls these intricate cellular processes. My studies aim to identify novel strategies for the treatment of this complex blood cancer.
Grant: 6545-18 | Translational Research Program (TRP):
Location:Brigham and Women’s Hospital, Boston, Massachusetts 02241-3149
Project Title: Targeting Notch In B Cell Lymphoma/leukemiaProject Summary:
Remarkable progress has been made in the treatment of CLL and other B cell tumors such as mantle cell lymphoma, but to date none of these treatments result in cures, and new therapies are needed. Our group has a longstanding interest in targeting the Notch pathway as a cancer treatment strategy. Recently, mutations in Notch genes have emerged as being among the most important causes of CLL and other B cell tumors. These mutations result in Notch “hyperactivity” and are associated with more aggressive disease; thus, patients with tumors with Notch mutations are particularly in need of new therapies. Our proposed work is focused on the idea that even in tumor cells with Notch mutations, Notch activation depends on neighboring cells that express proteins called ligands that turn on Notch. The precise identity of these ligands is not known, but drug companies have developed therapeutic antibodies that specifically inhibit several known Notch ligands, including those that we think are responsible for Notch activation in B cell tumors. Our proposed studies aim to identify the ligand that is causing Notch activation in B cell tumors, to determine the reason that Notch causes B cell tumors to behave more aggressively, and to prove that Notch inhibitors, alone and in combination with other drugs currently used to treat CLL and other B cell tumors, are effective in killing tumor cells. Taken together, these studies will set the stage for new clinical trials of Notch inhibitors in patients with B cell tumors.
Grant: 6547-18 | Translational Research Program (TRP):
Location:The University of Adelaide, Adelaide, South Australia 5000
Project Title: Targeting Stromal Cell-derived Gremlin1 To Control Multiple Myeloma Disease DevelopmentProject Summary:
Multiple myeloma (MM) is a bone marrow (BM) cancer of antibody producing plasma cells (PC). MM PCs are thought to spread throughout the BM in a manner similar to the way in which solid tumours spread. However, which cells and/or factors within the BM are important in helping PCs establish and grow, remains largely unknown. Using newly developed microscopic and genetic marking techniques: we have shown that there are very few sites within the BM that are capable of supporting the growth of PC tumours. In fact, we have found that the majority of the PCs that migrate to, and “land” in the BM remain “dormant” and fail to grow. These findings suggest that in order to grow, MM PCs must encounter an environment that has the right type of cells and factors, which support their growth. We believe that a rare type of cell, called an osteochondroreticular stem cell (OCR-SC), which we recently discovered, plays an essential role in “switching on” the growth of MM PC. OCR-SCs are unique in their ability to make a protein called Gremlin 1 (Grem1), which has been shown in other types of cancer, to stimulate tumour growth. Our early studies show that Grem1 can potently stimulate MM PC growth and that very high levels of Grem1 are found in areas of the BM that are occupied by tumour. We have assembled a team of experienced researchers with unique skills and established relationships with industry to enable us to investigate whether inhibiting Grem1 activity can provide a way to limit the growth of MM PC and prevent MM disease development.
1. We will use a technique known as laser scanning cytometry (LSC) and BM samples from patients with a asymptomatic forms of MM known as monoclonal gammopathy of unknown significance (MGUS) or smouldering MM (SMM) and samples from patients with MM, to determine whether Grem1-expressing cells are found in areas of active tumour growth, and not in areas in which the PC remain dormant. Similarly, we will use LSC to examine the bones from mice in which we have induced a MM-like disease to show that Grem1-expressing OCR-SCs are a key component of the “activating” areas of BM which support MM PC growth.
2. We will use genetically altered mice, in which Grem1 has been removed from OCR-SCs, to show without doubt, that Grem1 is required for the growth and development of MM. In addition, we will inject an antibody that blocks the function of Grem1 into mice with MM, to see if this will lead to MM PC tumour death or dormancy. These studies will be the first important steps to see if Grem1 is a good therapeutic target to stop disease development in MM patients.
3. We will measure the levels of Grem1 in the blood in a large number of samples that we have collected from patients with MGUS, SMM or MM. This will allow us to determine if Grem1 levels are associated with the amount of disease a patient has, or whether Grem1 levels predict the risk of a patient with benign disease developing advanced disease.
Grant: 6532-18 | Translational Research Program (TRP):
Location:The Regents of the University of California, San Francisco, San Francisco, California 94143
Project Title: Inducing Effective Anti-leukemic Immunity With Novel AML Vaccines Expressing CD80/IL-15/IL-15R-alphaProject Summary:
Patients with high-risk acute myelogenous leukemia (AML) have poor outcomes because current drug regimens fail to eradicate disease. Transplants of bone marrow or peripheral blood stem cells from matched related, or unrelated donors (allo-transplants) improve survival due to elimination of residual AML by immune cells present in donor cell populations. However, many patients are not eligible for allo-transplants, either because they lack suitable donors, or because they have pre-existing conditions making transplant too risky. Other therapies based on stimulating anti-leukemic immune responses have been tested, but achieving reproducible clinical efficacy has been elusive. In one approach, patients’ AML cells are collected before treatment, frozen, and later used as inactivated cell vaccines in order to stimulate immune responses specific to patients’ own tumor. However, to date, anti-leukemic immunity stimulated by unmodified AML cell vaccines has been inadequate.
Our strategy to improve the efficacy of AML cell vaccines is to increase their immune stimulatory activity by viral mediated transfer of a unique combination of three genes. Viral constructs express 1) a protein required to initiate recognition by immune cells, CD80, 2) a hormone shown to stimulate unprecedented levels of anti-tumor immunity, IL-15, and 3) a carrier protein required for efficient production and secretion of IL-15 in leukemic cells, IL-15 receptor alpha (IL-15Ra). For proof of concept studies, vaccines were made by inactivating mouse AML cells with x-ray treatment to prevent introduction of live leukemia cells with skin injections. Serial vaccination with AML cells, in the absence of viral modification, was minimally effective in slowing progression of disease in leukemia-bearing mice. However, injection of mouse leukemia vaccines engineered to express IL-15/IL-15Ra/CD80, induced immune responses that permanently eradicated leukemia in 80% of vaccinated mice.
We now propose to test the effects of engineered, patient-derived AML cell vaccines in stimulating effective anti-leukemic responses. The function of a newly constructed lentivirus expressing human IL-15, IL-15Ra, and CD80, has already been validated in selected patient AML samples. Our aims are to: 1) quantify the level and duration of transferred gene expression in human AML; 2) evaluate the responses of immune cells from normal and leukemic individuals after stimulation with IL-15/IL-15Ra/CD80-expressing human AML cell vaccines. Responses will be evaluated both in cell culture, and by transplanting responding immune cells and human AML cells into immune deficient mouse models; 3) test the specificity of immune responses stimulated by IL-15/IL-15Ra/CD80-expressing AML cell vaccines by comparing effects of stimulated immune cells on AML versus normal bone marrow cells. The additional data provided by these studies will support the design and application for funding of a Phase 1 vaccine trial.
Grant: R6507-18 | Translational Research Program (TRP):
Location:Dana-Farber Cancer Institute, Boston, Massachusetts 02215
Project Title: MYD88 And CXCR4 WHIM-like Mutations Offer A Targeted Treatment Approach For WMProject Summary:
Ibrutinib is an active drug that is approved by the U.S. FDA and European Medicines Agency for the treatment of WM. WM patients who have a mutation in MYD88 (over 90% do) respond to ibrutinib, while those with mutations in CXCR4 show lower levels of response and delayed responses. Despite the overall high levels of response to ibrutinib among WM patients, the achievement of complete responses is lacking. We discovered as part of the LLS sponsored study that two important pathways exist by which mutated MYD88 can support growth and survival of WM cells. One pathway is mediated by BTK, a protein targeted by ibrutinib. The other pathway involves a family of proteins known as the IRAK proteins. We discovered as part of this work that the IRAK1 protein was particularly important in relaying survival signals, and that it remains turned on in tumor cells taken from patients with WM, whereas BTK is shutoff. This finding encouraged us to develop potent and selective inhibitors that target IRAK1. One compound that we developed (JH-X-119-01) potently blocked IRAK1, and was very selective for IRAK1. We showed that this compound could synergize with ibrutinib and kill more MYD88 mutated tumor cells, including WM cells and those derived from patients with aggressive lymphomas (ABC type), than Ibrutinib alone. While the activity of this compound is excellent in cell models it does not possess all the requisite parameters for evaluating its efficacy in preclinical murine models. We therefore propose to execute a medicinal chemistry campaign to achieve compounds simultaneously optimized for potency and drug like properties such as resistance to being degraded by liver enzymes and being able to be absorbed across the gut for therapy of MYD88 mutated diseases, including WM, ABC DLBCL, and primary brain lymphomas. During the course of our studies, we also pursued identifying other targets that are in the pathway that allow MYD88 mutated cells to grow. One target known as HCK was discovered that plays a master role as a regulator of many growth and survival pathways including BTK. We performed proof-of-concept studies with a toolbox compound, a compound that blocks HCK but is not suitable for use as a drug in humans, and showed this drug was very active in MYD88 mutated diseases. We propose to do medicinal chemistry to optimize this molecule for use in humans. During our studies, we also discovered that CXCR4 mutations found in 30-40% of WM patients cause resistance to ibrutinib. We worked out the signaling responsible for this resistance, and also found that blockers of CXCR4 reverse drug resistance. We developed a clinical trial that will open in the Spring 2017, and combine a CXCR4 blocker (ulocuplumab) with ibrutinib in WM patients who have the CXCR4 mutation. We will use advanced genetic technologies to see how CXCR4 mutated cells behave when a CXCR4 blocking agent is combined with ibrutinib.