Humanized Anti-CD19 Antibodies for B Cell Malignancy Treatment
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Solution Overview
Problem
Current therapeutic regimens for B cell malignancies, graft-versus-host disease, humoral rejection, and autoimmune diseases are limited in effectiveness, particularly for B cells that do not express or have low levels of CD20, and there is a need for improved reagents and methods targeting humoral immunity in transplant rejection.
Innovation Solution
Development of human, humanized, or chimeric anti-CD19 antibodies that bind to the human CD19 antigen, mediating complement-dependent cell-mediated cytotoxicity, antigen-dependent cell-mediated cytotoxicity, and apoptosis, with specific embodiments including antibodies HB12A and HB12B, and their variants, which can be used to treat B cell malignancies, autoimmune diseases, and prevent transplant rejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If anti-CD20 monoclonal antibody therapy is used to treat B cell malignancies, then treatment effectiveness is improved for CD20-expressing B cells, but treatment is ineffective for B cells that do not express or have low levels of CD20
Solution Approach 1:
The patent changes the target antigen parameter from CD20 to CD19. CD19 is expressed on a broader range of B cells including pre-B cells, immature B cells, and malignant B cells that may have lost CD20 expression. This parameter change allows the therapy to effectively target B cells that were previously resistant to anti-CD20 therapy, thereby resolving the contradiction between treatment effectiveness and applicability to different B cell types
2Measurement precision
If murine monoclonal antibodies are used for therapy, then high affinity binding to target antigen is achieved, but immunogenicity increases causing human anti-mouse antibody responses
Solution Approach 1:
The patent introduces a chimeric antibody structure that serves as an intermediary between murine and fully human antibodies. The variable regions (Fv) derived from murine antibodies provide high-affinity binding to CD19, while the constant regions are from human IgG1 or IgG3, reducing immunogenicity. This chimeric structure mediates between the high binding affinity of murine antibodies and the low immunogenicity of human antibodies, resolving the contradiction between measurement precision and harmful factors
Solution Approach 2:
The patent creates composite antibody molecules combining murine variable regions with human constant regions. This composite structure integrates the advantages of both murine and human antibodies: the murine Fv regions provide high-affinity CD19 binding, while the human constant regions reduce immunogenicity and enable effective complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) in human patients
3Reliability
If B cell depletion therapy is used to treat autoimmune diseases, then humoral immunity is reduced, but T cell-mediated autoimmune pathology remains unaffected
Solution Approach 1:
The patent develops antibodies with multi-functional effector mechanisms including complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), and induction of apoptosis. This multi-functionality allows the therapy to address both humoral immunity (through B cell depletion via CDC and ADCC) and potentially T cell-mediated pathology (through apoptosis induction and modulation of immune responses), thereby resolving the contradiction between effectiveness against humoral pathology and coverage of different autoimmune mechanisms
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The anti-CD19 antibodies effectively target and deplete B cells, including those that do not express CD20, offering improved treatment options for B cell malignancies and autoimmune diseases, and provide enhanced methods for preventing transplant rejection by targeting humoral immunity.
Implementation Method 1
complement-dependent cell-mediated cytotoxicity (CDC)
Implementation Method 2
antigen-dependent cell-mediated-cytotoxicity (ADCC)
Implementation Method 3
programmed cell death (apoptosis)
Data Source
AI summary
The present invention provides chimeric and humanized versions of anti-CD19 mouse monoclonal antibodies. The invention further relates to pharmaceutical compositions, immunotherapeutic compositions, and methods using therapeutic anti bodies that bind to the human CD19 antigen and that may mediate ADCC, CDC, and/or apoptosis for the treatment of B cell diseases and disorders, such as, but not limited to, B cell malignancies, for the treatment and prevention of autoimmune disease, and for the treatment and prevention of graft-versus-host disease (GVHD), humoral rejection, and post-transplantation lymphoproliferative disorder in human transplant recipients.