APBio is developing bi-specific antibodies with a focus on cancer immunotherapy with mechanisms including dual-targeting, targeted immunomodulation and dual-immunomodulation.
To do this, two pathways in the cancer immunity cycle are first identified where intervention of a selected target in each pathway shows a clinical benefit, and targeting at both pathways might suggest an additive or synergistic effect. Functional mono-specific antibodies for each target are generated and combination of selected antibodies tested for activity in functional assays.
Pair of antibodies with synergy are then selected and converted into bi-specific antibodies, and tested again in animal models for efficacy. The bi-specific antibody format selected by APBio is engineered to have properties similar to conventional IgG with symmetric assembly and bi-valent binding for each target, as well as good serum stability and pharmacokinetics for developability.