High-affinity monoclonal antibodies to glypican-3 and use thereof
Inventors
Ho, Mitchell • Phung, Yen T. • Gao, Wei • Zhang, Yifan
Assignees
US Department of Health and Human Services
Publication Number
US-9409994-B2
Publication Date
2016-08-09
Expiration Date
2033-05-31
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Abstract
Described herein is the identification of a panel of high affinity monoclonal antibodies that bind GPC3. The disclosed antibodies recognize native GPC3 on the surface of cancer cells, as well as soluble GPC3. The highest affinity antibody (YP7) was further characterized and shown to be highly sensitive in that it was capable of detecting cancer cells with low expression of GPC3. YP7 also exhibited significant HCC tumor growth inhibition in vivo. Immunotoxins comprising the antibodies disclosed herein fused to PE38 exhibited very high binding affinity for GPC3-expressing cells and significantly inhibited GPC3-expressing cancer cell growth. Thus, the high-affinity monoclonal antibodies disclosed herein can be used for the diagnosis and treatment of GPC3-expressing cancers.
Core Innovation
The invention concerns the identification and characterization of a panel of high-affinity monoclonal antibodies (mAbs) that specifically bind to glypican-3 (GPC3), a cell surface and soluble protein expressed in various cancers including hepatocellular carcinoma (HCC), melanoma, squamous cell carcinoma of the lung, and ovarian clear cell carcinoma. These antibodies, including YP7—the highest affinity mAb—can detect native GPC3 on the surface of cancer cells and soluble GPC3 in biological samples. The antibodies demonstrate high specificity and sensitivity, detecting cells with low GPC3 expression and inhibiting tumor growth in vivo.
The problem addressed by the invention is the lack of high-affinity monoclonal antibodies capable of detecting low levels of GPC3 expression in tumor cells, which has hampered GPC3-targeted cancer therapy and diagnostics. Existing monoclonal antibodies, such as 1G12, do not have sufficient affinity to measure serum GPC3 reliably or to detect GPC3 in low-expressing cancer cells, limiting their diagnostic and therapeutic utility. The invention solves this by providing mAbs with substantially improved affinity and specificity for GPC3, thus enabling more effective cancer diagnostics and immunotherapies targeting GPC3-expressing tumors.
Claims Coverage
The patent claims cover isolated monoclonal antibodies specific for glypican-3 and various compositions and methods related to their use, encompassing several inventive features.
Isolated monoclonal antibodies comprising specific heavy and light chain CDR sequences
Monoclonal antibodies that bind GPC3 wherein the heavy chain comprises specific complementarity determining regions (CDRs) set forth as SEQ ID NOs: 38, 39, and 40 or alternatively SEQ ID NOs: 41, 42, and 43; and the light chain comprises CDRs set forth as SEQ ID NO: 44, amino acid residues 56-58 of SEQ ID NO: 14, and SEQ ID NO: 45 or alternatively SEQ ID NOs: 46, 47, and 45.
Monoclonal antibodies comprising CDRs at defined amino acid residue positions in heavy and light chains
Antibodies wherein the heavy and light chains comprise CDR1, CDR2, and CDR3 at specified amino acid residue positions of SEQ ID NOs: 8, 12, 16, 20 and corresponding VL sequences SEQ ID NOs: 10, 14, 18, 22, 24, or 26.
Antibodies comprising heavy and light chain CDRs at alternative defined amino acid residue positions
Antibodies wherein the heavy and light chain CDRs correspond to slightly different positions within SEQ ID NOs: 8, 12, 16, 20 and corresponding light chain sequences.
Antibodies with heavy and light chain sequences having at least 90% or 95% identity
Antibodies comprising heavy chain amino acid sequences at least 90% or 95% identical to SEQ ID NOs: 8, 12, 16, 20 and light chain sequences at least 90% or 95% identical to SEQ ID NOs: 10, 14, 18, 22, 24, or 26.
Antibodies comprising exact heavy and light chain sequences
Antibodies wherein the heavy chain is SEQ ID NO: 8, 12, 16, or 37 and light chain is SEQ ID NO: 10, 14, 18, 22, 24, or 26.
Monoclonal antibodies comprising variable heavy and light domains of specified sequences
Antibodies containing a variable heavy (VH) domain comprising SEQ ID NO: 7, 11, 15, 19 or 36 and a variable light (VL) domain comprising SEQ ID NO: 9, 13, 17, 21, 23 or 25.
Monoclonal antibody fragments and isotypes
Antibodies including Fab, Fab′, F(ab)′2 fragments, single chain variable fragments (scFv), disulfide stabilized variable fragments (dsFv), and immunoglobulin G (IgG) isotype.
Labeled monoclonal antibodies
Monoclonal antibodies as above that are labeled with fluorescent, enzymatic, or radioactive labels.
Humanized monoclonal antibodies
Humanized versions of the monoclonal antibodies specific for GPC3.
Pharmaceutical compositions comprising the antibodies
Compositions comprising a therapeutically effective amount of the isolated monoclonal antibody and pharmaceutically acceptable carriers.
Immunoconjugates of the antibodies with effector molecules
Isolated immunoconjugates comprising the monoclonal antibody linked to an effector molecule, such as toxins (e.g., Pseudomonas exotoxin PE or variant PE38) or detectable labels.
Nucleic acids and expression vectors encoding the antibodies
Isolated nucleic acid molecules encoding the heavy and light chains of the antibodies, vectors comprising them, and host cells expressing them.
Methods of treating liver cancer using the antibody compositions
Methods of treating or inhibiting tumor growth or metastasis in subjects with liver cancer expressing GPC3 by administering therapies comprising the disclosed antibodies or immunoconjugates.
Methods of detecting GPC3 in tissue samples
Methods of detecting GPC3 in tissue samples by contacting the sample with the monoclonal antibody and detecting antibody binding, optionally using labeled antibodies or secondary antibodies.
Chimeric antigen receptors and bispecific antibodies comprising the antibodies
Chimeric antigen receptors (CARs) and bispecific antibodies containing the GPC3-specific monoclonal antibodies for therapeutic applications.
The patent claims comprehensively cover isolated monoclonal antibodies binding GPC3 with defined CDR and variable domain sequences, labeled and humanized forms, immunoconjugates with toxins or labels, nucleic acid constructs, methods for cancer diagnosis and treatment using these antibodies, and engineered therapeutic agents including CARs and bispecific antibodies, thereby providing broad protection to these high-affinity anti-GPC3 antibody embodiments and their uses.
Stated Advantages
The antibodies have high affinity and specificity for GPC3, enabling detection of cancer cells with low GPC3 expression.
YP7 antibody showed significant tumor growth inhibition in vivo, indicating therapeutic potential.
Immunotoxins comprising the antibodies fused to PE38 exhibited very high binding affinity and effectively inhibited growth of GPC3-expressing cancer cells.
The antibodies can be used in both diagnosis and treatment of GPC3-expressing cancers.
Documented Applications
Diagnosis of cancers expressing GPC3, including hepatocellular carcinoma (HCC), melanoma, squamous cell carcinoma of the lung, and ovarian clear cell carcinoma through detection of GPC3 in tissue or serum samples.
Treatment of GPC3-expressing cancers by administration of high-affinity monoclonal antibodies or immunoconjugates linked to cytotoxic agents such as Pseudomonas exotoxin (PE38).
Use of antibodies to inhibit tumor growth or metastasis in subjects with GPC3-expressing cancers.
Generation of chimeric antigen receptor (CAR) T cells expressing the antibody binding fragment for immunotherapy.
Production of bispecific antibodies targeting GPC3 and T cell receptor components for cancer immunotherapy.
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