Framework residue substituted humanized COL-1 antibodies and their use
Inventors
Kashmiri, Syed • Schlom, Jeffrey • Padlan, Eduardo A.
Assignees
US Department of Health and Human Services
Publication Number
US-8828717-B2
Publication Date
2014-09-09
Expiration Date
2025-12-30
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
The present disclosure provides humanized COL-1 monoclonal antibodies that retain CEA binding affinity, compared to a parent antibody. Also disclosed herein are humanized COL-1 monoclonal antibodies that have reduced immunogenicity, compared to a parent antibody. The disclosed humanized COL-1 antibodies include substitution of framework residues with residues from the corresponding positions of a homologous human sequence. In several embodiments, methods are disclosed for the use of a humanized COL-1 antibody in the detection or treatment of a CEA-expressing tumor or cell in a subject. Also disclosed is a kit including the humanized COL-1 antibodies described herein.
Core Innovation
The present disclosure provides humanized COL-1 monoclonal antibodies that retain carcinoembryonic antigen (CEA) binding affinity, compared to the parent antibody HuCOL-1AbrCDR. These humanized COL-1 antibodies include substitution of framework residues with residues from corresponding positions of a homologous human sequence. Specific substitutions are made in the heavy chain framework at positions such as 20, 27, 38, 48, 67, 68, 79, 81, 1, and 12 of SEQ ID NO: 8. The antibodies also exhibit reduced immunogenicity compared to the parent antibody.
The problem addressed is the inherent immunogenicity of murine monoclonal antibodies, such as COL-1, when administered to humans. The human anti-murine antibody (HAMA) response limits their clinical use due to allergic reactions and rapid clearance. Attempts to humanize murine antibodies by grafting murine CDRs onto human frameworks reduce the number of immunogenic murine residues, but some framework residues previously thought essential for antigen binding were retained, which still evoke immune responses. There is a need to develop a humanized COL-1 antibody with both high binding affinity and reduced immunogenicity for clinical use.
The disclosure relates to humanized COL-1 antibodies derived from HuCOL-1AbrCDR by substituting one or more murine framework residues with human residues at corresponding Kabat positions to minimize murine content and immunogenicity without compromising CEA binding affinity. Variants such as FRV4, FRV7, and FRV10 contain progressively fewer murine residues in the heavy chain framework and retain or improve CEA binding affinity compared to the parent antibody. The disclosure also encompasses antibodies linked to effector molecules for therapeutic or diagnostic use and methods for detecting or treating CEA-expressing tumors using these humanized antibodies.
Claims Coverage
The patent claims cover eight main inventive features related to nucleic acids encoding humanized COL-1 monoclonal antibodies with specific framework residue substitutions, vectors and host cells expressing said nucleic acids, and conjugated antibodies with detectable labels.
Humanized COL-1 antibodies with specified heavy chain framework substitutions
An isolated nucleic acid encoding a humanized COL-1 monoclonal antibody with a heavy chain comprising SEQ ID NO: 8 and a light chain comprising SEQ ID NO: 4, including specified substitutions at heavy chain framework positions 1, 12, 20, 27, 38, 48, 67, 68, 79, and 81 of SEQ ID NO: 8, wherein the antibody retains binding affinity for CEA.
Humanized COL-1 antibodies conjugated to detectable labels
Isolated nucleic acids encoding humanized COL-1 antibodies as described, further comprising a conjugated detectable label, where the label is a fluorescent or radioactive molecule.
Vectors comprising nucleic acids encoding humanized COL-1 antibodies
Vectors including a promoter operably linked to nucleic acids encoding the humanized COL-1 antibodies with the framework substitutions.
Host cells transformed with vectors expressing humanized COL-1 antibodies
Isolated host cells, notably eukaryotic cells, transformed with the vectors encoding the humanized COL-1 antibodies.
Humanized COL-1 antibodies with variable heavy and light chain sequences as SEQ ID NO: 12 and SEQ ID NO: 9
Isolated nucleic acids encoding humanized COL-1 antibodies comprising the VH sequence of SEQ ID NO: 12 and the VL sequence of SEQ ID NO: 9, retaining CEA binding affinity compared to HuCOL-1AbrCDR.
Humanized COL-1 antibodies with variable heavy and light chains as SEQ ID NO: 12 and SEQ ID NO: 4
Isolated nucleic acids encoding humanized COL-1 antibodies with the heavy chain of SEQ ID NO: 12 and light chain of SEQ ID NO: 4, optionally conjugated to detectable labels.
Humanized COL-1 antibodies with variable heavy and light chains as SEQ ID NO: 13 and SEQ ID NO: 4
Isolated nucleic acids encoding antibodies with heavy chain SEQ ID NO: 13 and light chain SEQ ID NO: 4, optionally conjugated to detectable labels.
Humanized COL-1 antibodies with variable heavy and light chains as SEQ ID NO: 14 and SEQ ID NO: 4
Isolated nucleic acids encoding antibodies with heavy chain SEQ ID NO: 14 and light chain SEQ ID NO: 4, optionally conjugated to detectable labels.
The claims collectively cover the nucleic acid sequences encoding humanized COL-1 monoclonal antibodies with defined framework substitutions that retain CEA binding affinity, their expression vectors and host cells, and conjugations to detectable labels, thus encompassing the production and use of minimally immunogenic humanized COL-1 antibodies.
Stated Advantages
The humanized COL-1 antibodies have reduced immunogenicity compared to murine and earlier humanized versions, minimizing HAMA response.
The antibodies retain or improve high binding affinity to carcinoembryonic antigen (CEA).
Humanized antibodies with fewer murine residues are more suitable for repeated administration in humans.
Antibodies demonstrate comparable or enhanced binding to cell-surface CEA and serum samples, indicating clinical usefulness.
Variants with framework substitutions show decreased sera reactivity, suggesting potential for reduced immunogenic response in patients.
Combination therapy with radiolabeled antibodies and vaccine enhances anti-tumor activity and survival in mouse models.
Documented Applications
Detection of CEA-expressing tumors or cells in subjects by administering humanized COL-1 antibodies that form immune complexes with CEA for in vivo or in vitro localization and imaging.
Treatment of subjects with CEA-expressing tumors using therapeutically effective amounts of the humanized COL-1 monoclonal antibodies, alone or conjugated to cytotoxins or radioactive isotopes.
Combination therapy with humanized COL-1 antibodies and immunogenic agents (vaccines) to enhance anti-tumor immune responses, reducing tumor growth and improving survival.
Use of humanized COL-1 antibodies linked to detectable labels for radioimmunoguided surgery to localize and remove tumors.
Production of humanized COL-1 antibodies via recombinant expression in host cells transformed with nucleic acids encoding the variant antibodies.
Interested in licensing this patent?