PROJECT 1 – Combination Activated T-Cell and Vaccine Therapy in Myeloma
Basic Sciences Principal Investigator: Larry W. Kwak, M.D., PhD (MD Anderson)
Clinical Sciences Principal Investigator: Muzaffar H. Qazilbash, M.D. (MD Anderson)
Basic Sciences Co-PI: Carl H. June, M.D. (Penn)
Clinical Sciences Co-PI: Edward A. Stadtmauer, M.D. (Penn)
Significant progress has been made in developing and validating methods to induce immunity in patients with hematologic malignancies. A central hypothesis of this application is that multiple biologic and immunologic maneuvers are required to achieve long-term control of these cancers. A promising new approach involves combining tumor-specific vaccines with vaccine-primed adoptive T-cell transfer. Our team has developed a candidate vaccine, Id-KLH that targets the patient-specific and tumor-specific M-protein that is produced by myeloma cells. This vaccine has proved effective as a single agent in phase II and III clinical trials. Adoptive immunotherapy with vaccine primed T cells, following high-dose chemotherapy and autologous hematopoietic stem cell transplantation (SCT), has also shown encouraging results in patients with myeloma in phase I/II trials. Furthermore, we provided the first evidence in humans that combining adoptive immunotherapy with vaccination could result in the generation of protective chemotherapy within weeks following the SCT. Based on these promising clinical results, and on the safety and feasibility of this clinical trial, we will conduct a series of clinical trials to induce tumor-specific immunity in patients with myeloma. The two Specific Aims below will test the hypothesis that vaccines can be combined with adoptive immunotherapy in patients with myeloma with the goal of generating a molecularly targeted and potent antitumor immunity:
Specific Aim 1: Conduct a phase II clinical trial to study the feasibility and immunogenicity of post-transplant effector T-cell reconstitution and idiotype-KLH vaccination in patients with advanced myeloma.
Specific Aim 2: Determine whether the combination immunotherapy regimen augments myeloma immunity and decreases tumor burdens.
PROJECT 2 – Anti-2-Microglobulin Antibodies as Therapeutic Agents for Multiple Myeloma
Basic Sciences Principal Investigator: Qing Yi, M.D., Ph.D. (MD Anderson)
Clinical Sciences Principal Investigator: Michael Wang, M.D. (MD Anderson)
Myeloma tumor cells can survive even the most aggressive treatment available today, leading to disease relapses. The long-term goal of this project is to develop more effective therapies that slow cell growth and multiplication and eradicate myeloma cells. We recently made a novel and exciting discovery that anti-2-microglobulin (2M) monoclonal antibodies (mAbs) had strong apoptotic activity in both established myeloma cell lines and primary myeloma cells from patients. The mAbs selectively target and kill myeloma cells in coculture with normal hematopoietic cells without damaging normal blood cells, including CD34+ stem cells. Myeloma cell death induced by anti-2M mAbs was not blocked by myeloma growth and survival factors, such as soluble 2M and IL-6. The mAbs induced cell death by inhibiting PI3K/Akt and ERK pathways and activating JNK pathways. They compromise mitochondrial integrity, leading to cytochrome c release and activation of a caspase-9-dependent cascade, both needed for apoptosis. The mAbs were also active and therapeutic in vivo in xenograft mouse models of myeloma. Our hypothesis is that anti-2M mAbs may be used as therapeutic agents to treat patients with MM; it will be tested by the following Specific Aims:
Specific Aim 1: Examine the mechanisms of anti-2M mAb-induced apoptosis in myeloma cells with a focus on MHC class I and class-I-like molecules and intracellular signaling pathways.
Specific Aim 2: Enhance the efficacy of anti-2M mAbs by utilizing immune effector cells, molecules, or agents.
Specific Aim 3: Overcome drug resistance by combination therapy of anti-2M mAbs with novel antimyeloma agents.
Specific Aim 4: Generate humanized anti-2M mAbs and conduct preclinical and clinical studies to examine the toxicology, pharmacokinetics, safety, and biological effects of the mAbs.
PROJECT 3 – Targeting the HDM-2 E3 Ligase in Multiple Myeloma
Basic Sciences Principal Investigator: Robert Z. Orlowski, M.D., Ph.D. (MD Anderson)
Clinical Sciences Principal Investigator: Donna M. Weber, M.D. (MD Anderson)
The ubiquitin-proteasome pathway has been validated as a therapeutic target for multiple myeloma (MM) by our group and others through the demonstration of the activity of bortezomib in both the relapsed/refractory and up-front settings. Because of its broad impact on intracellular proteolysis, however, this proteasome inhibitor induces anti-apoptotic effects at the molecular level that decrease its efficacy, and at the clinical level it induces toxicities. Therefore, the use of a more targeted approach, such as inhibiting a specific E3 ubiquitin ligase responsible for ubiquitination of only a small subset of client proteins, would likely be more effective and better tolerated. We have obtained evidence that second-generation small molecule inhibitors of the HDM-2 E3 ligase, which is best known for its role in p53 ubiquitination, induce anti-proliferative effects in MM models irrespective of their p53 status; that these agents activate a p53-dependent type I cell death program, as well as p53-independent type II cell death, or autophagy; and that they interact synergistically with different classes of chemotherapeutics in wild-type and mutant p53 backgrounds. These and other findings led us to our central hypothesis that HDM-2 inhibitors are promising novel agents that can be used as chemosensitizers in a p53 status-adapted approach to personalize MM therapy and to individualize the therapy to the characteristics of each patient’s disease. To evaluate this possibility, and to translate these agents into the clinic, we propose the following Specific Aims:
Specific Aim 1: Further define the molecular mechanisms of action of HDM-2 inhibitors in MM, including their impact on type I and II cell death, and the role of p53 and HDM-2 in these processes.
Specific Aim 2: Delineate the pathways by which HDM-2 inhibitors sensitize MM to type I-inducing chemotherapeutics such as anthracyclines, death receptor agonists, and Bcl-2 inhibitors in wild-type p53 models, and to mTOR inhibitors in mutant p53 models.
Specific Aim 3: Pilot an HDM-2 inhibitor as a single agent in a phase I study evaluating its impact and mechanism of cell death induction in patients with relapsed/refractory MM, in preparation for later studies of an individualized p53 status-adapted approach.
PROJECT 4 – Targeting Multiple Myeloma by Combining CDK Inhibitors and BCL-2 Antagonists
Basic Sciences Principal Investigator: Steven Grant, M.D. (VCU)
Clinical Sciences Principal Investigator: Michael Wang, M.D. (MD Anderson)
Basic Sciences Co-principal investigators: Yun Dai, M.D., Ph.D. (VCU), Paul Dent, Ph.D. (VCU)
The goal of this study is to develop a novel therapeutic strategy for patients with refractory MM, involving agents that interrupt DNA damage checkpoints and an important survival signaling pathway. Evidence linking dysregulation of cell cycle and Bcl-2 family proteins in the molecular pathogenesis of MM has prompted intense interest in cyclin-dependent kinase (CDK) inhibitors and Bcl-2 antagonists in this disease. Furthermore, recent findings suggest that certain CDK inhibitors (e.g., flavopiridol, FP) act as transcriptional repressors by inhibiting the CDK9/cyclinT pTEFB complex and, by extension, phosphorylation of the carboxy-terminal domain of RNA polymerase II. Such agents down-regulate expression of short-lived proteins including Mcl-1, a critical survival factor in MM. Significantly, CDK inhibitors have recently been found to enhance the lethality of Bcl-2 antagonists (e.g. ABT-737) in human leukemia cells by unleashing Bak from Bcl-xL and Mcl-1, leading to a dramatic potentiation of apoptosis. Notably, a novel FP schedule has recently been developed that displays significant activity in another B-cell malignancy (CLL). Therefore, we hypothesize that clinically relevant CDK inhibitors such as FP, seliciclib (R-roscovitine), and SCH727965 (an agent with an IC50 of 1 nM toward CDK9), represent logical candidate agents to enhance the activity of clinically relevant Bcl-2 antagonists (e.g., GX15-070, ABT-737) in MM. Indeed, preliminary evidence suggests a high degree of synergism between FP and GX15070, as well as other CDKI/Bcl-2 antagonist regimens, in MM cells. Evidence also suggests that such regimens induce upregulation of pro-apoptotic proteins (e.g., Bim, NOXA, and BIK) which may cooperate with Mcl-1 downregulation to trigger apoptosis.
Specific Aim 1: Employ genetic tools to test the hypothesis that synergistic interactions between CDK inhibitors and Bcl-2 antagonists stem from Mcl-1/XIAP downregulation; upregulation of Bim, NOXA, and BIK; release of Bak and BIM from both Bcl-xL and Mcl-1; activation of Bax/Bak; and induction of mitochondrial injury.
Specific Aim 2: Determine whether and by what mechanism(s) this strategy overcomes conventional drug resistance, stromal/cell adhesion- or growth factor-mediated drug resistance, and bortezomib or lenalidomide resistance in MM cells.
Specific Aim 3: Evaluate the selectivity of this strategy by comparing its activity against primary, patient-derivedCD138+ MM versus its normal counterparts (e.g., CD138-, CD34+ cells), and testing its in vivo efficacy using flank and systemic xenograft MM models.
Specific Aim 4: Initiate one or more Phase I trials of CDKIs (e.g., FP) and Bcl-2 antagonists (e.g., GX15-070) in patients with refractory MM to provide a rational foundation for a novel approach to MM therapy, in which the activity of clinically relevant Bcl-2 antagonists (e.g., GX15-070 or ABT-737) is enhanced through rational combination with transcriptionally repressive CDK inhibitors that disrupt the pTEFb complex (e.g., FP or SCH727965) in such patients.