James L. Rubenstein, M.D., Ph.D. - US grants

human therapy evaluation; meningitis; neoplasm /cancer relapse /recurrence; antineoplastics; neoplasm /cancer chemotherapy; monoclonal antibody; clinical trial phase I; pharmacokinetics; patient oriented research; human subject; clinical research;

DESCRIPTION (provided by applicant): The non-Hodgkin's lymphomas (NHL) represent a major cause of cancer-related morbidity and death. There are approximately 56,000 new cases of non-Hodgkin's lymphoma each year in the U.S., resulting in over 25,000 deaths annually. Approximately 10-20% of NHL cases involve the brain. CNS involvement of NHL is associated with an adverse prognosis and can occur by two distinct pathways: primary CNS lymphoma and secondary dissemination of systemic lymphoma to the brain. Beyond the fact that the majority of these tumors express the cell surface molecule CD20, there is an extreme paucity of molecular information regarding the biological basis of CNS involvement of NHL. New treatments are needed to treat these complications. The goal of this proposal is to begin to use targeted therapies to treat CNS lymphomas and to define the biological basis for drug resistance and possibly CNS tropism in these tumors. Ultimately, insights into the molecular features which underlie CNS involvement may lead to the development of more rational therapeutics to treat or to prevent these complications. This proposal has three specific aims: One, to perform a phase I clinical trial which investigates the safety and potentially the efficacy of intrathecal administration of the anti-CD20 antibody, rituximab, in patients with recurrent lymphomatous meningitis. Two, to use this trial a mechanism for the procurement of lymphomatous meningitis specimens for gene expression profile analysis to determine the mechanistic basis for dissemination of lymphoma cells within the leptomeninges and the basis for drug resistance which commonly is manifest within the leptomeningeal compartment. Three, to identify prognostic markers in primary CNS lymphoma. Our experience suggests that there are at least two subtypes of primary CNS lymphoma, one which is sensitive to methotrexate-based therapy and which is associated with prolonged survival, and one which manifests drug-resistance and is associated with early progression. We will perform gene expression profile analysis of these tumors from diagnostic specimens obtained from a frozen tumor bank to identify a set of genes, which can be used to predict outcome.

DESCRIPTION (provided by applicant): The long term objectives of this project are to define mechanisms of tumor-induced immune suppression of macrophage function. Macrophages are a critical component of anti- tumor immunity but may be subverted from the classically-activated, or M1 phenotype, which mediates tumor elimination, to an alternatively-activated, M2 phenotype, which promotes tumor progression. Interleukin-4 (IL-4) signaling through its receptor, IL-4R-a, is a pivotal regulator of macrophage polarization to the M2 phenotype. Disruption of IL-4 signaling may therefore represent a useful strategy to attenuate the subversion of tumor immunity mediated by M2 tumor- associated macrophages. Our general strategy is to define the phenotypic characteristics of tumor macrophages from patients with non-Hodgkin's lymphoma who participate in a phase I immunotherapy trial involving the administration of anti-CD20 antibody into the cerebrospinal fluid in patients with recurrent disease in the brain. In addition, we will use genetic and pharmacologic strategies in mouse models to dissect the effect of cytokine signaling on tumor angiogenesis, macrophage phenotype and immunotherapeutic response in a model of CNS lymphoma. The specific aims are to define the relationship between IL-4 signaling, macrophage differentiation, lymphoma growth and response to anti-CD20 antibody. We envision five goals: (1) Define subpopulations of tumor macrophages within the CSF and their relationship to IL-4-induced programming, (2) Define the relationship between macrophage polarization to the M2 phenotype and resistance to anti-CD20 antibody, (3) Define the relevant cytokines and chemokines which predict this resistance, (4) Evaluate the relationship between IL-4 expression by tumor vessels, M2 macrophage programming and tumor growth, (5) Determine the impact of defects in cytokine signaling on macrophage polarization and response to anti-CD20 antibody. Results of these studies will have implications for a variety of disorders and cancers in which immune surveillance as well as antibody-dependent cell-mediated cytotoxicity are important means of disease control. These studies may lead to the development of new therapies which modulate macrophage programming and potentiate their anti-tumor potency. PUBLIC HEALTH RELEVANCE: The long term objectives of this project are to define mechanisms of tumor-induced suppression of macrophage function in patients. Macrophages are a critical component of anti- tumor immunity but may be subverted from the classically-activated, or M1 phenotype, which mediates tumor elimination, to an alternatively-activated, M2 phenotype, which promotes tumor progression. Interleukin-4 (IL-4) signaling through its receptor, IL-4R-a, is a pivotal regulator of macrophage polarization to the M2 phenotype. Disruption of IL-4 signaling may therefore represent a useful strategy to attenuate the subversion of tumor immunity mediated by M2 tumor- associated macrophages. Our general strategy is to perform an innovative, multidisciplinary set of studies to test the hypothesis that IL-4 promotes lymphoma growth both by supporting the tumor blood supply and by the subversion of macrophage function. Results of these studies will promote the development of more effective therapies not only for non-Hodgkin's lymphoma, but also for other malignancies in which immune surveillance as well antibody-dependent cell-mediated cytotoxicity are important means of disease control.

DESCRIPTION (provided by applicant): The long-term objectives of this project are to define mechanisms of tumor- induced immune suppression of macrophage function. The innate immune system has significant potential to control cancer progression, however the specific molecular cues and pathways by which myeloid cells recognize and target cancer cells are largely undefined. Using murine models combined with phase I investigation; we have demonstrated that IFN-?-associated M1 features of tumor-associated macrophages within the lymphoma microenvironment are associated with tumor responses and prolonged survival. We now propose a multidisciplinary approach that tests our hypotheses regarding mechanisms by which the systemic as well as innate immune response within the brain may control CNS lymphoma progression. Our general strategy is to evaluate lymphoma-associated macrophages in mouse models using in vivo imaging and gene knock-out strategies to define the origin of myeloid cells in the brain that mediate tumor phagocytosis as well as to identify the key signaling pathways involved in lymphoma recognition. The specific aims are to identify the key receptors and signaling pathways used by macrophages to control lymphoma progression. We envision four goals. (1) Determine the role of the systemic myeloid response in CNS lymphoma, (2) Determine the key receptors and signaling pathways used by macrophages to recognize and elicit phagocytosis of CNS lymphoma, (3) Evaluate the impact of conditional deletions of myeloid genes on lenalidomide and rituximab-dependent responses on CNS lymphoma growth, (4) Identify factors within the CNS microenvironment that attenuate the systemic innate and adaptive immune response to CNS lymphoma. Results of these studies will have implications for a variety of disorders and cancers in which immune surveillance as well as antibody-dependent cell-mediated cytotoxicity are important means of disease control. These studies may lead to the development of new therapies that modulate macrophage programming and potentiate their anti-tumor potency as well as the adaptive immune response.

DESCRIPTION (provided by applicant): The long-term objectives of this project are to develop innovative therapies for patients with high-risk or refractory CNS lymphomas. Current genotoxic strategies used in clinical trials have achieved a plateau in anticipated progression-free survival for newly- diagnosed patients. There is a clear unmet need for the development and integration of more effective therapies for the greater than 40% of patients who progress during the first six months with conventional therapy, as well as for the increasing proportion of older patients who do not tolerate high-dose chemotherapy or brain irradiation. We propose an innovative strategy to evaluate cutting-edge targeted therapies that we hypothesize will disrupt key survival pathways in high-risk CNS lymphoma tumors. In addition, we will evaluate these candidate approaches using novel, patient-derived CNS lymphomas generated from chemotherapy-refractory specimens. Our general strategy is to comprehensively evaluate the efficacy of four candidate targeted therapies in preclinical mouse models of patient-derived CNS lymphomas. We will also test the hypothesis that these agents may have collateral effects on the innate immune response mediated by tumor-associated macrophages and microglia. The specific aims are to determine the response of the pharmacologic disruption of candidate key survival pathways, BCL6, MYC, JAK/STAT and/or Btk pathways in CNS lymphoma, using novel, patient-derived, xenograft mouse models of CNS lymphoma. We will also determine the pharmacodynamic impact of these agents on tumor physiology and metabolism. In addition, we will evaluate these agents in combination with relevant established pharmaceutical compounds that have demonstrated efficacy in CNS lymphoma and in these mouse models: rituximab, temozolomide, lenalidomide. Finally, we will test the hypothesis that lead candidates evaluated may have collateral impact on the myeloid response within the CNS and potentially synergize with or attenuate the efficacy of established agents. Results of these studies will facilitate the development of innovative therapeutic strategies that address an unmet need for CNS lymphoma patients and accelerate the evaluation of rationally-defined, potent combinations in early phase trials. Furthermore, these studies will have implications for a variety of disorders in which immune surveillance as well as antibody-dependent cell-mediated cytotoxicity are important means of disease control.

PROJECT SUMMARY/ABSTRACT This proposal will apply an innovative metabolic imaging approach, hyperpolarized (HP) 1-13-C MRI to address NF-kB activation in cancer. NF-kB is a key pro-survival transcriptional regulator that drives resistance in a variety of malignancies, one of which is primary CNS lymphoma (PCNSL) a highly refractory form of activated B-cell (ABC)-type large cell lymphoma. ABC-type large cell lymphomas are an important cause of cancer-related mortality worldwide. Recent trials using targeted agents that block NF-kB activation have shown activity in PCNSL and systemic ABC-type lymphoma, yet responses last only a few months, suggesting that alternative pathways of NF-kB activation are adaptively induced to mediate resistance. We hypothesize that HP 1-13-C MRI may have particular utility in detecting clinical response, defining prognosis and target inhibition in PCNSL and can also be applied to identify effective combinatorial strategies that durably suppress NF-kB activation. In addition, we envision that this approach may be impactful in identifying biomarkers that predict efficacy of immunotherapy. Our team recently demonstrated for the first time the feasibility of HP 1-13-C MRI to image malignant glioma in patients. These studies support the potential of HP 1-13-C MRI to identify metabolites that yield impactful non-invasive biomarkers of in vivo metabolic processes in PCNSL, including resistance pathways, with markedly improved sensitivity and specificity compared to standard MRI. We have recruited a talented, multidisciplinary team to pursue this highly translational project to address key gaps in PCNSL research through pursuit of the following specific Aims: 1) Test the hypothesis that hyperpolarized (HP) [1-13-C]-metabolic MR imaging of genetically-defined, patient- derived orthotopic models of PCNSL can non-invasively evaluate depth of response to combinations of NF-kB targeting agents as well as provide an early biomarker of the emergence of resistance. 2) Test the hypothesis that HP [1-13-C] metabolic MR metrics can be developed as non-invasive biomarkers of NF-kB-activation and immunosuppression in a syngeneic, immunocompetent model of PCNSL. 3) Perform the initial proof of principle patient studies of HP 13C MRI to determine feasibility and methods of HP [1-13C] pyruvate MRI as a real time, non-invasive imaging tool for response assessment in PCNSL. We will correlate genetic markers of NF-kB activation in tumors with lactate on HP 13C MRI and lactate in cerebrospinal fluid and their relationship to progression-free survival. These studies will constitute a basis for integration of HP13C metabolic imaging in the research of PCNSL, and of ABC-type lymphomas in general, to improve detection, prognostication, identify resistance, and facilitate precision medicine. We anticipate these studies will identify novel combinations and schedules of agents that durably block NF-kB, to be tested in the clinic. These studies may also provide a rationale for implementation of tumor lactate as a novel biomarker for immunotherapy trials. Ultimately our studies may stimulate multicenter trials to evaluate HP 13C MRI in PCNSL.