Single-domain antibodies (sdAbs) are a class of heavy-chain only antibodies (HCAbs) initially identified in camelids and sharks. In light of their characteristics of small molecular size, good stability, high solubility, and high penetration in various tissues, sdAbs emerge as an ideal structural unit for developing multifunctional innovative biologics, and thus hold immense potential in oncology therapy.
Based on an in-depth understanding of the structure and function of sdAbs, we have established a comprehensive single-domain antibody platform encompassing the antibody screening, humanization, engineering and function characterization.
Based on the single-domain antibody platform, Alphamab Oncology developed KN035 product, which is a Fc fused single domain antibody against PD-L1. Leveraging the advantages of sdAbs in physicochemical properties, Alphamab Oncology further developed stable ultra-high concentration liquid formulation. KN035 was approved by Chinese authorities in November 2021 and became the world's first subcutaneously injectable PD-(L)1 inhibitor.
* Fei Zhang, Hudie Wei, Xiaoxiao Wang, Ting Xu, et al. Structural basis of a novel PD-L1 nanobody for immune checkpoint blockade. Cell Discovery,(2017) 3, 17004; doi:10.1038/celldisc.2017.4.
