Affinity matured CD22-specific monoclonal antibody and uses thereof
Inventors
Dimitrov, Dimiter S. • Zhu, Zhongyu • Ramakrishna, Sneha • Fry, Terry J.
Assignees
US Department of Health and Human Services
Publication Number
US-11939377-B2
Publication Date
2024-03-26
Expiration Date
2039-07-11
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
An affinity matured anti-CD22 human monoclonal antibody exhibiting significantly higher affinity (less than 50 pM) compared to the parental antibody (affinity of about 2 nM) is described. The anti-CD22 variant antibody or a fragment thereof, such as a single-chain variable fragment (scFv), can be used as the antigen-binding portion of chimeric antigen receptors (CARs), antibody-drug conjugates (ADCs), immunotoxins or multi-specific antibodies for the treatment of B-cell malignancies.
Core Innovation
This invention describes an affinity matured anti-CD22 human monoclonal antibody, designated m971-L7, which exhibits significantly higher binding affinity to the B cell antigen CD22 (less than 50 pM) compared to the parental antibody m971 (about 2 nM). The affinity matured antibody or an antigen-binding fragment such as a single-chain variable fragment (scFv) can be utilized as part of chimeric antigen receptors (CARs), antibody-drug conjugates (ADCs), immunotoxins, or multi-specific antibodies, offering novel therapeutic strategies against B-cell malignancies.
The problem addressed arises from the limitation of current CAR T cell therapies targeting B-cell malignancies, particularly in cases of acute lymphoblastic leukemia (ALL) that relapse due to loss or diminished expression of target antigens like CD19 or CD22. Patients who relapse exhibit poor CAR persistence or altered antigen expression, with diminished antigen density on leukemia cell surfaces leading to reduced CAR T cell activation and function. Thus, improving the affinity of anti-CD22 antibodies and strategies to overcome low antigen site density are needed to enhance CAR efficacy and durability of response.
The invention provides an affinity matured CD22-specific monoclonal antibody with enhanced binding properties, nucleic acid molecules encoding the antibody or CAR constructs comprising the antibody, and compositions including these antibodies for therapeutic or diagnostic use. Methods include detecting CD22 expression, treating B-cell malignancies with the antibody or cells expressing CARs incorporating the antibody, and combining treatment with agents that upregulate CD22 expression, such as Bryostatin 1, to overcome limitations posed by low antigen density.
Claims Coverage
The patent includes one independent claim encompassing a monoclonal antibody or antigen-binding fragment that binds CD22, and sets forth additional independent claims related to CARs, isolated cells expressing CARs, immunoconjugates, antibody-drug conjugates, multi-specific antibodies, antibody-nanoparticle conjugates, fusion proteins, nucleic acids encoding these molecules, and methods of detection and treatment.
CD22-specific monoclonal antibody with defined VH and VL CDR sequences
A monoclonal antibody or antigen-binding fragment comprising a variable heavy (VH) domain and variable light (VL) domain, where the VH domain includes the complementarity determining region (CDR) sequences of SEQ ID NO: 4 and the VL domain includes the CDR sequences of SEQ ID NO: 5.
Chimeric antigen receptor incorporating the CD22-specific antibody
A CAR comprising the disclosed monoclonal antibody or antigen-binding fragment targeting CD22, optionally including a hinge region, transmembrane domain, costimulatory signaling moiety, and signaling domain.
Isolated cells expressing the CD22-specific CAR
Cells, such as cytotoxic T lymphocytes, engineered to express the CD22-specific CAR for therapeutic use.
Immunoconjugate with antibody and effector molecule
An immunoconjugate comprising the CD22-specific monoclonal antibody or fragment and an effector molecule, which can be a toxin or a detectable label.
Antibody-drug conjugate comprising the CD22-specific antibody
An ADC formed by conjugating a drug to the disclosed CD22-specific monoclonal antibody or antigen-binding fragment.
Multi-specific antibody including the CD22-specific antibody
A bi- or tri-specific antibody comprising the CD22-specific antibody and at least one additional antibody or antigen-binding fragment.
Antibody-nanoparticle conjugate
A conjugate comprising a nanoparticle linked to the monoclonal antibody or antigen-binding fragment specific for CD22.
Fusion protein with CD22-specific antibody and heterologous protein
A fusion protein combining the CD22-specific monoclonal antibody or fragment with a heterologous protein or peptide, such as an Fc protein.
Nucleic acid and vectors encoding the CD22-specific antibody or related constructs
Nucleic acids encoding the CD22-specific monoclonal antibody, CAR, immunoconjugate, or fusion protein, including those operably linked to promoters and incorporated into vectors.
Methods of detecting CD22 expression
Methods of detecting CD22 in a sample by contacting with the monoclonal antibody or antigen-binding fragment and detecting binding, optionally using directly labeled antibodies or secondary antibodies.
Methods of treating CD22-positive cancers with CAR-expressing cells
Therapeutic methods administering isolated cells expressing the CD22-specific CAR to treat CD22-positive cancers, including B-cell malignancies like ALL and various lymphomas, optionally combined with Bryostatin 1.
Kits comprising the CD22-specific antibody and a CD22 upregulating agent
Kits containing the monoclonal antibody or antigen-binding fragment along with an agent that upregulates CD22 expression, such as Bryostatin 1, optionally including additional anti-cancer agents.
The claims collectively cover a high-affinity CD22-specific monoclonal antibody and antigen-binding fragments, associated CARs and CAR-expressing cells, various conjugates and fusion proteins incorporating the antibody, nucleic acid constructs encoding these molecules, methods of detection and treatment of CD22-positive malignancies, and kits combining the antibody with agents that enhance CD22 expression to improve therapeutic efficacy.
Stated Advantages
Significantly improved binding affinity of the anti-CD22 antibody (less than 50 pM) compared to the parental antibody (about 2 nM).
Enhanced efficacy of CAR T cell therapies by overcoming limitations associated with low antigen site density through increased antibody affinity and antigen upregulation strategies.
Improvement in CAR T cell persistence, memory formation, and durability of response against B-cell malignancies due to increased CD22 expression induced by agents like Bryostatin 1.
Potential for improved diagnostic sensitivity and specificity in detecting CD22 expression in samples from subjects with B-cell malignancies.
Documented Applications
Use of the affinity matured anti-CD22 monoclonal antibody or fragments as the antigen-binding portion of chimeric antigen receptors (CARs) for cellular therapy against B-cell malignancies.
Construction of antibody-drug conjugates (ADCs), immunotoxins, multi-specific antibodies, and antibody-nanoparticle conjugates that specifically target CD22-expressing cancer cells.
Detection and diagnosis of CD22 expression in samples to identify or confirm B-cell malignancies such as acute lymphoblastic leukemia and various lymphomas.
Combination therapies including administration of the CD22-specific antibody or CAR-expressing cells together with agents that upregulate CD22 expression, such as Bryostatin 1, to enhance antitumor effectiveness.
Interested in licensing this patent?