Descripció del projecte
– The problem: Glioblastoma multiforme (GBM) represents the most common and aggressive human primary brain tumor. Sadly, standard-of-care treatments based on surgery, chemotherapy, and radiation render dismal 5-year overall survival rates of 6%-22%, depending on age (American Cancer Society; www.cancer.org/). Novel, innovative, safe, and efficient targeted therapies are in high demand. – The solution: Adoptive cell immunotherapies (ACITs) have become a master player in the cancer immunotherapy field. The use of tumour infiltrating lymphocytes (TILs) and strategies redirecting T-cell cytotoxic function against cancer cells have contributed to save countless patients with advanced cancer. T-cell redirection relies on targeting a given tumour associated antigen (TAA) by the expression of membrane-anchored Chimeric Antigen Receptor (CAR) by T-cells (CAR T). The use of CAR Ts in hematological tumors have revolutionized the treatment of leukemias, lymphomas and multiple myeloma. Unfortunately, CAR T-cell therapy is more limited in solid tumors and novel strategies are required to improve its effectiveness, in particular to avoid tumor microenvironment immunosuppression.
– Therapeutic targets for GBM: The IL-13 receptor α 2 (IL-13Rα2) is a GBM associated antigen homogeneously expressed in GBM while showing very restricted expression in normal brain and tissues (Debinski W et al; Clin Cancer Res., 1999). IL-13Rα2 is overexpressed in 80% of GBM patients and its expression represents a poor prognostic factor due to its abundance in metastatic cells (Newman JP, et al. Nat Commun. 2017). IL-13Rα2 deregulation is also observed in colorectal metastatic, breast, melanoma, lung, and kidney cancers by activating biochemical pathways increasing tumor proliferation and invasion (Barderas R et al; Cancer Res. 2012; Jaén M et al; Cancers, 2021). Although IL-13Rα2 represents a robust therapeutic target for CAR T-cells in GBM, the immunosuppressive tumor microenvironment (iTME) severely compromises the expansion and activation of CAR T-cells, limiting their persistence and, therefore, their anti-tumoral performance. Anti-IL-13Rα2 monoclonal antibodies (MoAb) have been recently developed to block cell invasion, migration, and adhesion in IL-13Rα2+ cancer cells, and consequently, preventing liver and lung metastases (Jaén M et. al; Cancers, 2021). These MoAbs have been licensed to OneChain Immunotherapeutics (OCI) for CAR T-cell therapy. In addition, the laboratory of Dr. Pablo Menendez (OCI’s CSO, Josep Carreras Leukemia Research Institute, IJC) has characterized the role of some protein candidates with high expression in the iTME. In particular, we have identified OC_4 (confidential) as a bona fide surface marker highly expressed in iTME GBM, thus opening a new therapeutic avenue for dual targeting both GBM cells and the infiltrating cells from iTME.
-The project: OCI and IJC aim to collaborate in order to develop a dual CAR T-cell therapy for advanced/metastatic GBM targeting both cancer cells and the GBM-associated iTME (OC_4). Humanized single chain Fraction variable (scFv) from anti- IL-13Rα2 and anti-OC_4 MoAbs will be used for redirecting T-cells against GBM and iTME, respectively. Single (IL-13Rα2 and OC_4) and dual (bi-specific) second-generation CARs will be cloned in clinically validated lentiviral vectors (LVs) and assayed in cutting-edge in vitro and in vivo (immunodeficient and immunocompetent patient-derived xenografts (PDX)) models of GBM using primary GBM biopsies. We aim to complete the regulatory preclinical package in late 2025 to plan a Phase I clinical trial in 2026.
-Task Descriptions: First year (2023): i) generation of murine IL-13Rα2-CARs; ii) generation of proprietary anti-OC_4 hybridomas and subsequent murine CARs; iii) CAR cloning in LVs and viral production; iv) characterization of single CAR T-cells (transduction/activation/detection); v) humanization of the most efficient and specific murine CAR candidates (hCARs). Second year (2024): i) in vitro and in vivo validation of single hCAR T-cells in vitro (specificity and efficacy); ii) generation of IL-13Rα2/OC_4-directed dual hCAR; iii) in vitro characterization/validation of the specificity and efficacy of IL-13Rα2/OC_4 dual hCAR T-cells using GBM cell lines; iv) in vivo testing of intraventricular and intracranial delivery of IL-13Rα2/OC_4 hCAR T-cells in immunodeficient and immunocompetent PDXs. Orthotopic models based on patient’s biopsies will be established in collaboration with DR. Salvador Martinez (Neuroscience Institute, CSIC-UMH, Alicante). Third year (2025): i) pre-clinical in vitro and in vivo safety profile of the IL-13Rα2/OC_4 dual CAR T-cells; ii) CAR T-cell persistence studies based on re-challenge in vivo experiments; iii) patent application; iv) preparation of the Investigational Medical Product Dossier (IMPD) for phase I clinical trial; and v) thesis and scientific manuscript preparation.
