The monoclonal IgG-type antibodies were suggested comprising variable domains represented by a combination of VHH-derivative with a variable domain of the light chain V.sub.L. Said antibodies can comprise amino acid substitutions at positions 44 and 45 (Kabat numbering) or combinations thereof. Antibodies of the invention possess increased affinity and improved aggregation stability.

The present invention relates to the identification of key residues within mouse lgG3 antibodies (mAbs) that are responsible for intermolecular cooperativity and their transfer into lgG1 antibodies in order to enhance their functional affinity and direct cell killing.

The present invention provides antibodies that specifically bind to FLT3 (Fms-Like Tyrosine Kinase 3). The invention further provides bispecific antibodies that bind to FLT3 and another antigen (e.g., CD3). The invention further relates to antibody encoding nucleic acids, and methods of obtaining such antibodies (monospecific and bispecific). The invention further relates to therapeutic methods for use of these antibodies for the treatment of FLT3-mediated pathologies, including cancer such as Acute Myeloid Leukemia (AML).

The present disclosure relates to, inter alia, antibodies, or antigen-binding fragments thereof, that bind to C5a and to use of the antibodies in methods for treating or preventing complement-associated disorders such as, but not limited to, atypical hemolytic uremic syndrome, age-related macular degeneration, rheumatoid arthritis, sepsis, severe burn, antiphospho lipid syndrome, asthma, lupus nephritis, Goodpasture's syndrome, and chronic obstructive pulmonary disease.

The present invention relates to humanisation of antibodies in vivo. The invention provides non-human vertebrates, cells, populations and methods useful for humanising chimaeric antibodies in vivo. Using the present invention it is possible straightforwardly and rapidly to obtain antigen-specific antibodies that are fully human (ie, comprising human variable and constant regions) and have undergone recombination, junctional diversification, affinity maturation and isotype switching in vivo in a non-human vertebrate system. Furthermore, such antibodies are humanised (eg, totally human)—and selected—totally in vivo, and as such the present invention harnesses in vivo filtering for expressibility, affinity and biophysical characteristics in the context of the desired human variable and constant region pairings. This is avoids problems of down-grading antibody characteristics when humanising the constant region of chimaeric antibodies in vitro.

A binding domain or a multimer or a variant thereof which comprises a variable region encoded by a nucleic acid based on, derived or obtained from an animal phylogenetically distal from a human, which variable region is paired with a human variable region.

CDR-grafted antibody heavy and light chains comprise acceptor framework and donor antigen binding regions, the heavy chains comprising donor residues at at least one of positions (6, 23) and/or (24, 48) and/or (49, 71) and/or (73, 75) and/or (76) and/or (78) and (88) and/or (91). The CDR-grafted light chains comprise donor residues at at least one of positions (1) and/or (3) and (46) and/or (47) or at at least one of positions (46, 48, 58) and (71). The CDR-grafted antibodies are preferably humanized antibodies, having non human, e.g. rodent, donor and human acceptor frameworks, and may be used for in vivo therapy and diagnosis. A generally applicable protocol is disclosed for obtaining CDR-grafted antibodies.

The invention provides non-human cells and mammals having a genome encoding chimeric antibodies and methods of producing transgenic cells and mammals. Certain aspects of the invention include chimeric antibodies, humanized antibodies, pharmaceutical compositions and kits. Certain aspects of the invention also relate to diagnostic and treatment methods using the antibodies of the invention.

The invention provides non-human cells and mammals having a genome encoding chimeric antibodies and methods of producing transgenic cells and mammals. Certain aspects of the invention include chimeric antibodies, humanized antibodies, pharmaceutical compositions and kits. Certain aspects of the invention also relate to diagnostic and treatment methods using the antibodies of the invention.

Non-human animals (and/or non-human cells) and methods of using the same are provided, which non-human animals (and/or non-human cells) have a genome comprising human antibody-encoding sequences (i.e., immunoglobulin genes). Non-human animals described herein express antibodies that contain immunoglobulin (Ig) light chains characterized by the presence of human Vλ domains. Non-human animals provided herein are, in some embodiments, characterized by expression of antibodies that contain human Vλ light chains that are encoded by human Igλ light chain-encoding sequences inserted into an endogenous Igκ light chain locus of said non-human animals. Methods for producing antibodies from non-human animals are also provided, which antibodies contain human variable regions and mouse constant regions.