Anti-HIV domain antibodies and method of making and using same
Inventors
Dimitrov, Dimiter S. • Chen, Weizao
Assignees
US Department of Health and Human Services
Publication Number
US-9181327-B2
Publication Date
2015-11-10
Expiration Date
2029-01-07
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Abstract
The invention provides single domain antibodies and derivatives thereof that bind antigens of interest, which are stable, soluble, and do not tend to aggregate. The invention also provides methods for constructing a dAb library and methods for screening dAb libraries to identify the dAb of the invention. The invention also provide methods of treating or preventing conditions by antigen neutralization by administering the dAbs of the invention.
Core Innovation
The invention provides single domain antibodies (dAbs) and derivatives that bind antigens of interest, particularly HIV antigens, with high stability, solubility, and low tendency to aggregate. It offers methods for constructing dAb libraries and screening these libraries to identify antibodies of the invention. Therapeutic methods are also provided, utilizing these domain antibodies for treating or preventing conditions by antigen neutralization through administration of the dAbs.
The invention addresses problems known in the art, particularly the instability, poor solubility, and aggregation tendency of human-derived domain antibodies, which limit their suitability as therapeutics. Current anti-HIV therapies suffer from rapid viral resistance, and although monoclonal antibodies (mAbs) have been effective in various diseases, none have been approved for clinical use against HIV-1, mainly due to viral immune evasion and epitope accessibility issues. Full-size antibodies may be sterically hindered from accessing certain conserved epitopes like CD4-inducible (CD4i) epitopes on HIV, limiting neutralization efficiency.
The invention's core innovation includes the identification of a novel VH framework (the m0 framework) that can serve as a scaffold for highly diverse domain antibody libraries. This framework supports proper folding, high solubility, expression, and compatibility with diverse CDR sequences, overcoming prior limitations. A novel domain antibody named m36, derived from the library, exhibits potent neutralization of a broad range of HIV isolates with high specificity to CD4i epitopes. Fusion proteins containing the domain antibodies linked to stabilizing or enhancing agents further improve stability or neutralization potency. The invention also encompasses methods for preparing such libraries, screening for desired antibodies, and their therapeutic use against HIV.
Claims Coverage
The patent contains one independent claim focused on a defined isolated domain antibody and its structural features, along with dependent claims related to immunoconjugation and pharmaceutical compositions.
Isolated domain antibody with defined sequence identity and CDR features
An isolated domain antibody consisting of the amino acid sequence of m36 (SEQ ID NO: 96), or having at least 90% sequence identity to the framework amino acid sequence of m0 (SEQ ID NO:4), including (a) a CDR1 with a phenylalanine at positions 28 and 30 (Kabat numbering) and alanine, aspartate, serine or tyrosine at positions 27, 29, 31 and 32, and (b) at least one of CDR2 or CDR3 of m36 (SEQ ID NO: 96).
Immunoconjugation of the domain antibody to therapeutic agents
The domain antibody or fragment thereof can be immunoconjugated to one or more cytotoxic agents, chemotherapeutic agents, natural or synthetic toxins, radioactive isotopes, or antiviral agents.
Use of domain antibodies conjugated with antiviral agents
The antiviral agents immunoconjugated to the domain antibody can be selected from zidovudine, acyclovir, gangcyclovir, vidarabine, idoxuridine, trifluridine, ribavirin, foscarnet, amantadine, rimantadine, saquinavir, indinavir, amprenavir, lopinavir, ritonavir, adefovir, clevadine, entecavir, or pleconaril.
Pharmaceutical composition for treating HIV-1 infection
A pharmaceutical composition comprising a therapeutically effective amount of the domain antibody in accordance with the invention for treating HIV-1 infection.
Pharmaceutical composition including the isolated domain antibody and carrier
A composition comprising an effective amount of the domain antibody consisting of the amino acid sequence of m36 (SEQ ID NO: 96) and a pharmaceutically acceptable carrier.
The claims cover an isolated human single domain antibody m36 or variants thereof with defined CDR modifications, its conjugation to therapeutic and antiviral agents, and pharmaceutical compositions containing the domain antibody for treating HIV-1 infection.
Stated Advantages
The domain antibodies exhibit high stability, high solubility, and low aggregation tendency compared to prior art domain antibodies.
High affinity binding to epitopes, including sterically restricted HIV-1 CD4 inducible epitopes, enabling potent neutralization.
High expression levels facilitating therapeutic development.
The novel VH framework supports wide CDR diversity with proper folding and high soluble expression.
Fusion proteins with domain antibodies enhance stability and efficacy, including synergistic activity when combined with soluble CD4 or mimics.
Documented Applications
Treatment and prevention of HIV infections by administering therapeutically effective amounts of the domain antibodies or their fusion proteins.
Use of domain antibodies as therapeutics, prophylactics, diagnostics for HIV-1 infection.
Identification of antibodies that neutralize different clades and isolates of HIV-1 by screening phage-displayed domain antibody libraries.
Development of antibody conjugates with antiviral agents for HIV treatment.
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