Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-12473360-B2
Publication Date
2025-11-18
Expiration Date
Abstract
A multi-specific antibody contains at least one binding site for a cell specific antigen and at least one binding site for a tumor-reactive lymphocyte antigen and a multi-specific antibody including an IgG antibody or fragment thereof that binds to a first antigen; and at least one scFv antibody that binds to a second antigen that is different from the first antigen and is linked to a C terminus of at least one light chain or heavy chain of said IgG antibody or fragment. The multi-specific antibody reversibly binds to at least one of the cell specific antigen and tumor-reactive lymphocyte antigen or the first antigen and the second antigen with a greater affinity at an aberrant condition than at a normal physiological condition. Conjugates of the multi-specific antibodies and methods for generating the multi-specific antibody are also provided.
Core Innovation
The invention relates to a conditionally active multi-specific antibody that includes an IgG antibody or antigen binding fragment having at least one binding site for a cancer cell antigen, and an anti-CD3 scFv antibody that binds to a CD3 antigen. The anti-CD3 component is defined by having an amino acid sequence selected from SEQ ID NOs: 28, 30, 36, 44, 61, 62, 63, 64, 65, 66 and 71. At least one of the anti-CD3 scFv antibody and the IgG antibody or antigen binding fragment reversibly binds its antigen with greater affinity at a pH of 6.0 than at a pH of 7.4.
The disclosure frames the approach as exploiting reversibly conditionally active binding under an aberrant physiological condition than under a normal physiological condition, with the aberrant condition described in connection with acidic tumor and/or senescent microenvironments and low oxygen. A plurality of cancer cell antigen targets are described as compatible with the multi-specific format, including Axl, EpCAM, Her2, Ror2, B7-H3, neoantigens, Nectin4, and senescent cell antigens. The conditionally active feature is described as pH-conditionality, including a reversible binding behavior and a greater affinity/avidity ratio between aberrant and normal conditions.
The invention further encompasses antibody formats and construct generation concepts that support plug-and-play creation of new conditionally active multi-specific constructs. Binding components can be linked from known conditionally active lymphocyte binders to other antibody components, followed by linking and selecting reversibly higher-affinity binders. The antibody formats described include IgG/scFv configurations and fusion configurations, with example construct linkages including an scFv attachment at a specified location via a linker, and optional conjugation to macromolecules such as albumin and PEG.
Claims Coverage
The document contains one independent claim directed to a conditionally active multi-specific antibody with a cancer cell antigen-binding IgG or fragment and an anti-CD3 scFv, where the reversible binding affinity is greater at pH 6.0 than at pH 7.4. The independent claim provides the core structural and functional limitations, while dependent claims refine the lymphocyte context, enumerated cancer-cell antigen targets, additional pH-dependent affinity constraints, defined sequence IDs for specified antibody components, and example conjugation and fusion/attachment format constraints.
Conditionally active multi-specific antibody with reversible pH-enhanced affinity
A conditionally active multi-specific antibody comprising an IgG antibody or antigen binding fragment having at least one binding site for a cancer cell antigen, and an anti-CD3 scFv antibody binding a CD3 antigen, wherein the anti-CD3 scFv amino acid sequence is selected from the group consisting of SEQ ID NOs: 28, 30, 36, 44, 61, 62, 63, 64, 65, 66 and 71, and at least one of the anti-CD3 scFv antibody and the IgG antibody or antigen binding fragment reversibly binds to its antigen with a greater affinity at a pH of 6.0 than at a pH of 7.4.
Reversible greater affinity at pH 6.0 versus pH 7.4 for both antigen binding sites
The conditionally active multispecific antibody binds both a cancer cell antigen and a CD3 antigen with greater affinity at pH 6.0 than at pH 7.4.
Cancer cell antigen selected from Axl, EpCAM, Ror2, Her2, B7-H3, or Nectin4
The conditionally active multispecific antibody uses a cancer cell antigen selected from Axl, EpCAM, Ror2, Her2, B7-H3, or Nectin4.
CD3 antigen located on specified lymphocytes
The conditionally active multispecific antibody defines the CD3 antigen as located on a lymphocyte selected from T cells, Jurkat cells, NK cells, or lymphokine-activated killer cells.
Defined sequence-ID IgG variable regions for anti-Axl and anti-B7-H3 variants with pH-dependent reversible binding
The conditionally active multispecific antibody includes an IgG or antigen-binding fragment that is either an anti-Axl or an anti-B7-H3 antibody with defined variable-region sequences, and both the anti-CD3 scFv and the IgG or fragment reversibly bind their respective antigens with higher affinity at pH 6.0 than at pH 7.4.
Conjugation to a macromolecule selected from albumin or polyethylene glycol
A conjugated conditionally active multi-specific antibody uses a macromolecule selected from albumin or polyethylene glycol.
Overall claim coverage centers on conditionally active multi-specific antibodies that include anti-CD3 scFv and an IgG or antigen-binding fragment for cancer cell antigen binding, with a reversible binding profile characterized by greater affinity at pH 6.0 than at pH 7.4, optionally refined by the pH-dependent greater-affinity requirement for both binding sites, enumerated cancer-cell antigen targets, specified lymphocyte contexts for CD3, sequence-ID-defined antibody variable regions, and example macromolecule conjugation.
Stated Advantages
Greater affinity/reversible binding at pH 6.0 than at pH 7.4 for at least one of the anti-CD3 scFv and the IgG or fragment components.
Conditionally enhanced binding behavior linked to pH-conditional reversible activity under an aberrant physiological condition relative to a normal physiological condition.
Reduced peripheral T-cell activation relative to a non-conditional benchmark in a mouse xenograft study described in the disclosure.
Documented Applications
Tumor treatment using a conditionally active multi-specific construct in a mouse xenograft model, where EpCAM×CAB-CD3 achieves tumor regression with reduced peripheral T-cell activation versus a non-conditional benchmark antibody.
Assessment of pH-dependent binding and functional tumor-reactive lymphocyte activity using ELISA pH-dependent binding results for CD3×(Axl/Her2/B7-H3/EpCAM) and Jurkat functional stimulation assays showing pH-conditional activity [procedural detail omitted for safety].
Interested in licensing this patent?