High affinity monoclonal antibodies targeting glypican-2 and uses thereof
Inventors
Ho, Mitchell • Li, Nan • Fleming, Bryan D.
Assignees
US Department of Health and Human Services
Publication Number
US-12012463-B2
Publication Date
2024-06-18
Expiration Date
2039-08-06
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Monoclonal antibodies that bind glypican-2 (GPC2) with high affinity are described. Immunotoxins and chimeric antigen receptors (CARs) that include the disclosed antibodies or antigen-binding fragments thereof are further described. In some instances, the antibody or antigen-binding fragment is humanized. The disclosed GPC2-specific antibodies and conjugates can be used, for example, for the diagnosis or treatment of GPC2-positive cancers, including neuroblastoma, medulloblastoma and retinoblastoma.
Core Innovation
The invention describes high affinity monoclonal antibodies that specifically bind glypican-2 (GPC2), isolated via mouse hybridoma technology, and referred to as CT3 and CT5. These antibodies specifically bind GPC2 and not other glypican family proteins. The antibodies, or antigen-binding fragments thereof, can be used to form immunotoxins, chimeric antigen receptors (CARs), multi-specific antibodies, antibody-drug conjugates (ADCs), antibody-nanoparticle conjugates, or fusion proteins. Humanized variants of the antibodies are also described. The invention discloses methods and compositions involving these antibodies for diagnosis and treatment of GPC2-positive pediatric cancers including neuroblastoma, medulloblastoma, and retinoblastoma.
The problem addressed is the urgent need for safe and effective treatments for neuroblastoma and similar pediatric solid tumors that currently suffer from poor survival rates and high relapse rates. A significant challenge is the lack of tumor-specific targets for therapy. GPC2 is uniquely expressed in the nervous system and mRNA is highly expressed in neuroblastoma and other pediatric cancers, making it a promising tumor-specific target. The invention overcomes the difficulty of targeting solid tumors by providing monoclonal antibodies highly specific to GPC2 that show tumor selective binding and potent therapeutic activity in vitro and in vivo.
Claims Coverage
The claims include one independent claim directed to monoclonal antibodies and antigen-binding fragments targeting GPC2, and additional independent claims related to chimeric antigen receptors (CARs), nucleic acid molecules encoding CARs, isolated cells expressing CARs, immunoconjugates, antibody-drug conjugates (ADCs), multi-specific antibodies, antibody-nanoparticle conjugates, fusion proteins, vectors, compositions, and therapeutic and diagnostic methods.
Monoclonal antibodies specific for GPC2
Monoclonal antibodies or antigen-binding fragments comprising a variable heavy (VH) domain and variable light (VL) domain, wherein the VH and VL domains comprise complementarity determining regions (CDRs) of SEQ ID NOs: 2 and 4 or SEQ ID NOs: 6 and 8, respectively, defined by Kabat, IMGT, Paratome or combinations thereof. The antibodies include humanized variants and various sets of CDR residues within the VH and VL domains. The antibodies specifically bind GPC2 with high affinity.
Chimeric antigen receptors comprising GPC2-specific antibodies
CARs including the GPC2-specific monoclonal antibodies or antigen-binding fragments, optionally comprising a hinge region (such as CD8α hinge), a transmembrane domain (such as CD8α transmembrane domain), co-stimulatory signaling moiety (such as 4-1BB), and an intracellular signaling domain (such as CD3ζ).
Cellular therapies expressing GPC2-targeted CARs
Isolated cells, including cytotoxic T lymphocytes (CTLs), expressing the CARs comprising GPC2-specific antibodies as antigen-binding moieties for targeting GPC2-positive cancer cells.
Immunoconjugates and antibody-drug conjugates
Immunoconjugates comprising the disclosed GPC2-specific monoclonal antibody or antigen-binding fragment linked to an effector molecule such as Pseudomonas exotoxin or a detectable label (fluorophore, enzyme, radioisotope). ADCs comprising the antibody conjugated to a drug, including cytotoxic small molecules (such as anti-microtubule agents, anti-mitotic agents, or cross-linking agents).
Multi-specific antibodies
Multi-specific antibodies, such as bispecific antibodies, comprising the GPC2-specific antibody and an additional monoclonal antibody or antigen-binding fragment that specifically binds other targets such as T cell receptor components (e.g., CD3) or natural killer cell activating receptors (e.g., CD16).
Antibody-nanoparticle conjugates and fusion proteins
Compositions comprising GPC2-specific antibodies conjugated to nanoparticles such as liposomes, dendrimers, micelles, or polymeric nanoparticles, and fusion proteins combining the antibody with heterologous proteins or peptides, including Fc proteins.
Nucleic acids, vectors, and compositions
Nucleic acid molecules encoding the monoclonal antibodies, antigen-binding fragments, CARs, and other constructs, optionally operably linked to promoters; expression vectors including lentiviral vectors; and pharmaceutical compositions containing the antibodies or related constructs in pharmaceutically acceptable carriers.
Methods of treatment and detection
Methods of treating GPC2-positive cancers in subjects by administering therapeutically effective amounts of the antibodies, CAR-expressing cells, immunoconjugates, ADCs, multi-specific antibodies, or compositions described; and methods of detecting GPC2 expression in samples using the disclosed antibodies or antigen-binding fragments.
The claims comprehensively cover the isolated high affinity GPC2-specific monoclonal antibodies and their antigen-binding fragments, associated therapeutic constructs such as CARs and immunoconjugates, compositions, nucleic acids, vectors, and methods of treating and diagnosing GPC2-positive cancers, emphasizing the specificity and therapeutic utility of the antibodies in pediatric oncology and related applications.
Stated Advantages
The antibodies exhibit high affinity and specificity for GPC2, binding only to human GPC2 and not other glypican family members.
The antibodies specifically detect GPC2 expression in tumors such as neuroblastoma, medulloblastoma, and retinoblastoma, but not in normal tissues, indicating tumor-specificity.
CAR T cells incorporating the antibodies demonstrate potent and specific killing of GPC2-positive tumor cells in vitro and induce tumor regression in vivo.
Immunotoxins based on the antibodies selectively kill GPC2-expressing tumor cells and inhibit tumor growth in animal models with good tolerability.
Documented Applications
Diagnosis of GPC2-positive cancers using the antibodies in immunohistochemistry, immunoassays, or detection methods on tumor biopsies or biological samples.
Treatment of GPC2-positive pediatric cancers including neuroblastoma, medulloblastoma, and retinoblastoma using antibodies, CAR T cells, immunoconjugates, antibody-drug conjugates, multi-specific antibodies, or antibody-nanoparticle conjugates.
Use of CAR T cells engineered with GPC2-specific antibodies for immunotherapy of metastatic neuroblastoma in animal models.
Use of antibody-based immunotoxins incorporating Pseudomonas exotoxin variants for inhibiting tumor growth and prolonging survival in mouse xenograft models.
Interested in licensing this patent?