Extensive physicochemical and biological characterization of BP02, a trastuzumab biosimilar, and comparative assessment with Herceptin

Trastuzumab is an IgG1 monoclonal antibody that targets the extracellular HER2 domain on HER2 + cancer cells. CuraTeQ biologics has developed a trastuzumab biosimilar, code named BP02, aimed at treating early and metastatic breast cancer and metastatic gastric cancer. This biosimilar has been thoroughly characterized through physicochemical and biological methods in accordance with established guidelines. The primary, secondary, and tertiary structures were evaluated using analytical techniques, which indicated that BP02 shares structural similarities with Herceptin. Evaluations of size and charge variants revealed that BP02 possesses comparable levels of both high and low molecular weight species. Although minor differences in charge variants were observed in BP02 when compared to Herceptin, these differences were not deemed biologically significant. Furthermore, glycan heterogeneity and post-translational modifications were comparable in both BP02 and Herceptin. Biological studies were conducted to assess the inhibition of cancer cell proliferation, the primary mechanism of action of trastuzumab. Additional known mechanisms of trastuzumab, including antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis, were also evaluated. BP02 demonstrated comparable biological activities across all assays and was found to be on par with Herceptin. Moreover, the binding activities and affinities of the HER2 receptor, FcRn, and other Fc receptors were assessed and determined to be similar. In summary, BP02 was found to exhibit similarities in both physicochemical and biological properties compared to Herceptin.