Biological Technologies, Department of Analytical Development and Quality Control, Genentech-a Member of the Roche Group, South San Francisco, California, 94080, USA.
Sci Rep. 2019 Mar 7;9(1):3900. doi: 10.1038/s41598-019-40689-1.
T-cell-dependent bispecific antibodies (TDBs) are promising cancer immunotherapies that recruit a patient's T cells to kill cancer cells. There are increasing numbers of TBDs in clinical trials, demonstrating their widely recognized therapeutic potential. Due to the fact that TDBs engage and activate T cells via an anti-CD3 (aCD3) arm, aCD3 homodimer (aCD3 HD) and high-molecular-weight species (HMWS) are product-related impurities that pose a potential safety risk by triggering off-target T-cell activation through bivalent engagement and dimerization of T-cell receptors (TCRs). To monitor and control the level of unspecific T-cell activation, we developed a sensitive and quantitative T-cell-activation assay, which can detect aCD3 HD in TDB drug product by exploiting its ability to activate T cells in the absence of target cells. This assay provides in-vivo-relevant off-target T-cell-activation readout. Furthermore, we have demonstrated that this assay can serve as a platform assay for detecting T-cell-activating impurities across a broad spectrum of aCD3 bispecific molecules. It therefore has the potential to significantly benefit many T-cell-recruiting bispecific programs.
T 细胞依赖性双特异性抗体（TDBs）是一种很有前途的癌症免疫疗法，它可以招募患者的 T 细胞来杀死癌细胞。越来越多的 TBD 正在临床试验中，这证明了它们被广泛认可的治疗潜力。由于 TDB 通过抗 CD3（aCD3）臂、aCD3 同源二聚体（aCD3 HD）和高分子量物质（HMWS）来募集和激活 T 细胞，因此这些物质是与产品相关的杂质，通过二价结合和 TCR 二聚化，可能会引发非特异性 T 细胞激活，从而带来潜在的安全风险。为了监测和控制非特异性 T 细胞激活的水平，我们开发了一种敏感和定量的 T 细胞激活测定法，该方法可以通过利用 aCD3 HD 在没有靶细胞的情况下激活 T 细胞的能力来检测 TDB 产品中的 aCD3 HD。该测定法提供了与体内相关的非特异性 T 细胞激活的读出结果。此外，我们已经证明，该测定法可以作为一种平台测定法，用于检测广泛的 aCD3 双特异性分子中的 T 细胞激活杂质。因此，它有可能使许多招募 T 细胞的双特异性项目受益。
