Children s Hospital of Philadelphia Annual Progress Report: 2011 Formula Grant

Transcription

1 Children s Hospital of Philadelphia Annual Progress Report: 2011 Formula Grant Reporting Period January 1, 2012 June 30, 2012 Formula Grant Overview The Children s Hospital of Philadelphia received $3,521,179 in formula funds for the grant award period January 1, 2012 through December 31, Accomplishments for the reporting period are described below. Research Project 1: Project Title and Purpose Highly Active Cell Therapy of Cancer Our purpose is to develop engineered T cell therapies for B cell malignancies, leukemias, and certain specific solid tumors such as neuroblastoma and synovial sarcoma. Using chimeric antigen receptors (CARs) which target tumors and activate T cells, and an efficacious clinical-grade (GMP) ex vivo cell manufacturing system, we will continue our highly promising use of CAR-engineered T cells. This grant will support preclinical studies to optimize CARs in mouse xenograft models, as well as early phase clinical trials testing a variety of CAR-mediated T cell therapy approaches. Anticipated Duration of Project 1/1/ /31/2015 Project Overview The overall goal of this project is to develop clinically efficacious methods of treating high-risk and relapsed leukemia, lymphoma and some solid tumors with chimeric antigen receptor (CAR)- armed T cells. The long-term goal of our cell therapy group is to establish improved treatments for hematologic malignancies and other tumors by engineering, optimizing, and clinically testing these highly active anti-cancer T cells. This treatment approach could potentially obviate the need for allogeneic stem cell transplant for some patients. Our preliminary clinical data showing cures of patients with high burdens of refractory tumor provide the first clear proof of concept and proof of mechanism for an anti-cancer cell therapy, and are potentially paradigm-shifting. They suggest that the central problems of expansion and persistence of therapeutic cells in the patient after infusion are solvable using the right cell manufacturing system and the right CAR design. With successful expansion and long-term persistence in the patient, even small doses of T cells can lyse very large tumor burdens. In order to leverage the dramatic results we have seen and continue to develop these approaches for pediatric cancer patients, we are proposing a 4 year combined basic/translational cell therapy program for CHOP. We propose 3 Aims to build on these results and establish cell therapy infrastructure at CHOP: Children s Hospital of Philadelphia 2011 Formula Grant Page 1

2 Aim 1. Develop novel CARs targeting antigens other than CD19, and develop RNA transfection as an alternative approach to lentiviral transduction to temporarily express CARs on T cells. Aim 2. Perform 3 cell therapy trials testing CD19-targeted CAR+ T cell approaches in patients with B cell malignancies such as acute lymphoblastic leukemia (ALL), CLL and non-hodgkin lymphoma (NHL). Aim 3. Using CARs and approaches developed in Aim 1, take engineered T cell-based therapy into trials enrolling non-b cell cancers, including sarcoma (target NY-ESO-1), acute myelogenous leukemia (AML; target mesothelin), and neuroblastoma (target GD2). Principal Investigator Stephan A. Grupp, MD, PhD Professor of Pediatrics The Children s Hospital of Philadelphia 3501 Civic Center Blvd. Philadelphia, PA Other Participating Researchers David Barrett, MD PhD employed by The Children s Hospital of Philadelphia Carl H. June, MD; Bruce L. Levine, PhD; Yangbing Zhao, MD PhD employed by the University of Pennsylvania Expected Research Outcomes and Benefits Expected outcomes and benefits include the following: 1. Initiate a trial to test CAR-T cell therapy in children with CD19+ malignancies. CARs are chimeric antigen receptors that redirect T cells to cancer cells and activate the T cells so they kill the tumor. Any cancer target or tumor-associated antigen which is recognized by an antibody can in principle be made into a CAR. 2. Develop mrna-based CARs to supplement permanent modification of T cell by lentivirus. We anticipate gaining a better understanding of the performance of mrna CAR+ T cells in animal models that will guide our use of them in the clinic. 3. A better understanding of the nature and phenotype of long-term engrafting T cells and their impact on disease control in animal models. 4. Extend the CD19 CAR concept to mrna CARs and to the allogeneic transplant setting. 5. Develop CARs that can target non B cell tumor antigens, to test CARs against AML and solid tumors. 6. Further develop clinically relevant xenograft models of pediatric cancer, translating data from these models to clinical trial design. 7. The overall goal is improve treatment options for patients with high-risk and relapsed cancers. Children s Hospital of Philadelphia 2011 Formula Grant Page 2

3 Summary of Research Completed Project milestone(s) for the period 1/1/2012-6/30/2012: 1. Begin protocol submission, 2. Patient recruitment processes, and 3. Hiring new personnel. The long-term goal of our cell therapy group is to establish improved treatments for leukemias and other tumors by engineering, optimizing, and clinically testing these highly active anticancer T cells. This treatment approach could potentially replace expensive and risky bone marrow transplants for some patients. The researchers are at a very exciting time for these new treatments, having shown in the past year the first clinical results that T cell engineered with chimeric antigen receptors (CARs; Figure 1) will persist long-term after infusion, expand in the patient, and eliminate very high tumor burdens. The work, supported by the CURE grant, has been directed toward testing the hypothesis that pediatric cancers can be targets for CARengineered T cells. The Researchers have made excellent progress on the Aims in this short initial period of the grant. Aim 1. Develop novel CARs targeting antigens other than CD19, and develop RNA transfection as an alternative approach to lentiviral transduction to temporarily express CARs on T cells. The investigators have now created both RNA and lentiviral versions of CARs targeting GD2. In a very short time, Dr. Barrett has developed several luciferase-expressing human NB cell lines and taken these to create both flank (localized) and disseminated mouse models using immunodeficient NSG mice (Figure 2). The luciferase technology allows researchers to image disease burden and location over time in the living animal, and the innovative 2-color approach also allows researchers to measure colocalization of engineered T cells and tumor cells in the mice that the researchers are treating with cell therapies. The investigators have begun to use these GD2 CAR+ T cells in treatment experiments, and are already seeing an impact of T cell treatment on NB in the animals. The results of two such experiments, which are ongoing at the time of this report, are shown in Figure 3. Another interesting and potentially significant experiment looks at the issue of long term T cell protection. In this experiment, the investigators took a small cohort of mice that had been cured of their ALL (a primary pediatric ALL). This was a xenografted ALL sample from a child with very high risk ALL which investigators made luciferase+ and which has been used for therapeutic modeling. A single dose of CAR+ T cells (19-BBzeta or 19-28BBzeta "triple" CARs) achieved this cure. The cured mice were then rechallenged with ALL after 4 months. We rechallenged with the same dose of ALL cells and saw the increase in survival and evidence of memory activity in the pattern of leukemia control (Figure 4). One mouse (#344) rejected the ALL rechallenge within days and was cured again, while the other mice controlled the disease for a period of time. This is the first time that CAR+ T cells have shown this degree of persistence and memory function in an in vivo model. In other experiments, the investigators have engineered RNA-based CAR+ T cells and shown that multiple infusions of these temporarily modified cells can control disease. Experiments are underway to show that multiple infusions can replace permanently modified (lentivirally transduced) CAR+ T cells. Children s Hospital of Philadelphia 2011 Formula Grant Page 3

4 Aim 2. Perform 3 cell therapy trials testing CD19-targeted CAR+ T cell approaches in patients with B cell malignancies such as acute lymphoblastic leukemia (ALL), CLL and non-hodgkin lymphoma (NHL). In 2011, we treated the first adult patients with these engineered T cells. The preliminary clinical experience in the first patients is nothing short of ground-breaking. The data show we can eradicate large amounts (literally pounds) of treatment-resistant cancer cells and can put patients with no treatment options into long-term remissions. This is the first time that anyone has seen these kinds of responses to a cell-based therapy. This was described as a top 10 science advance in Discover Magazine in their year-end issue ( This is the work which sets the stage for ongoing cell therapy project. These results are potentially paradigm-shifting in the field of cell therapy for cancer. What's needed for success of cell therapy is expansion and persistence of transferred cells in the patient after infusion, and we believe this happens when using the right, clinical-grade cell manufacturing system and the right CAR design. Our group believes the manufacturing approach is key, and may possibly be more important than the CAR design. With successful expansion and long-term persistence in the patient, even small doses of T cells can destroy very large amounts of tumor. Status of the clinical trials. In order to leverage the dramatic results we have seen and continue to develop these approaches for pediatric cancer patients, researchers are now starting to aggressively move these therapies into early phase clinical trials for children with cancer treated at CHOP. Our first pediatric clinical trial is now open, IRB-approved, and recruiting patients at CHOP (milestones 1 and 2 complete). This trial uses lentiviral CARs targeted to CD19 for B cell malignancies (these cases are mostly ALL in children). This trial is CHP-959: PILOT STUDY OF REDIRECTED AUTOLOGOUS T CELLS ENGINEERED TO CONTAIN ANTI-CD19 ATTACHED TO TCRζ AND 4-1BB SIGNALING DOMAINS IN PATIENTS WITH CHEMOTHERAPY RESISTANT OR REFRACTORY CD19+ LEUKEMIA AND LYMPHOMA. The second and third cell therapy trials, using allogeneic CART19 cells and RNA-transfected CART19 cells, are being written at this time. Aim 3 proposes using CARs and approaches developed in Aim 1 to take engineered T cell-based therapy into trials enrolling non-b cell cancers, including sarcoma (target NY-ESO-1), acute myelogenous leukemia (AML; possible target mesothelin or CD123), and neuroblastoma (target GD2). Further progress in Aim 1 over the next year will direct the approaches for Aim 3. Personnel recruitment. An experienced animal technician, Jessica Hulitt, has been recruited and is working full time on these cell therapy experiments. Christine Strait has also been hired as the Data Manager/Protocol Coordinator for the cell therapy studies. Thus, milestone 3 is also complete. Children s Hospital of Philadelphia 2011 Formula Grant Page 4

5 Figure 1. Structure of a chimeric antigen receptor (CAR) Figure 2. Disseminated model of neuroblastoma. Bioluminescent images of disseminated neuroblastoma. 2x10 6 SY5Y cells, which were lentivirally transduced to express GFP and Click Beetle Green luciferase, were injected into the mouse tail vein. Disease burden was detectable as early as day 3. At sacrifice, the liver was found to have a heavy burden of disease with marrow involvement as well. Children s Hospital of Philadelphia 2011 Formula Grant Page 5

6 Figure 3. Disseminated neuroblastoma treated with lentivirus-transduced T cells. PBS: untreated mice (5 mice); NTD: mice treated with untransduced T cells (3 mice); GD2: mice treated with GD2 CAR (2 mice). GD2 CAR T cells were ~55% CAR positive at time of administration. Children s Hospital of Philadelphia 2011 Formula Grant Page 6

7 Figure 4. Rechallenge with leukemia. In this experiment, we took a small cohort of mice that had been cured of a primary pediatric ALL. The cured mice were then rechallenged with ALL after 4 months. Images show lack of luc+ ALL in mice that temporarily (323) and permanently (344) controlled the disease. The graph below shows photon emission from the mice (representing disease burden). The green curve shows temporary disease control, the blue curve a second cure, and the light blue and orange curves the course of untreated ALL. Children s Hospital of Philadelphia 2011 Formula Grant Page 7