Our integrated antibody discovery platform, combining cell panning of a proprietary fully-human antibody phage display library, in vitro epitope selection and cell-based functional assays, allowing us to generate antibody leads efficiently with desirable functionality on native targets of both cell membrane-bound receptors and their soluble ligands, as well as conformation epitopes.
All functional leads isolated are further subjected to evaluation of drug-like properties for better developability, including post-translational modification, expressibility, solubility, aggregation, serum stability, and pharmacokinetics studies, etc.. Mutagenesis and chain replacement may be applied to the leads for improved properties if needed.
The Omni-Mab is a proprietary fully-human antibody phage display library for readily generation of nM affinity, functional antibody leads for therapeutics against drug targets of various conformations and epitopes. Some characterizations of the library are described below:
Leaky expression of some human antibody fragments in bacteria during library construction and amplification is toxic to the cells, leading to lower than expected integrity of the library and diversity of full-length clones. When this happens during library panning, some desirable antibody clones isolated in the beginning might be lost forever with apparent deletion in the antibody DNA fragment. The Omni-Mab library has been engineered for reduced toxicity from leaky expression, and to preserve presentation of rare Vh and Vk germline frameworks and the integrity of antibody clones through the panning process.
All antibodies in the library are sequences naturally occurred in human bodies expected to exhibit lower immunogenicity and higher stability in serum.
The Omni-Mab contains antibody Fab fragments which have the same configuration as the antigen-binding domain of a full-length IgG. This would ensure better heavy/light chain pairing and facilitate easy conversion of isolated high affinity Fabs into full-length IgGs without losing its binding activity, folding/assembly and integrity.
The library is composed of more than 1 x 1011 full-length Fab sequences with heavy and light chain variable regions derived from 130 donors. As a result, 0.1 nM affinity antibodies against protein antigens, even self-antigens, are usually isolated from the library after three rounds of panning without the need for affinity engineering.
In addition to sequence diversity, Omni-Mab also covers all structural diversity of 51 heavy chain and 71 light chain human antibody germline frameworks, confirmed by next-generation sequencing. It’s been suggested that different antibody germline frameworks might be selected preferably against certain types of antigens during an immune response. Therefore, the germline CDR canonical structure diversity gives the library better conformation and epitope coverage for any given target.
The Omni-Mab library, combined with our panning process, screening and assay platforms, has allowed us to generate several high-affinity antibodies of desirable functionality and mechanism-of-action with potential therapeutic applications against self-antigens, including soluble factors and immune checkpoint targets. These antibodies may either block protein/protein interaction, modulate immune cell function, or bind to conformational epitope on a heterodimeric receptor which might be difficult to make with conventional immunization or B cell cloning strategy.