Figure 4
The anti-CLDN18.2 ADC and anti-CLDN18.2 CD3 Bispecific inhibit growth of different hCLDN18.2-tumor cells. The anti-CLDN18.2 ADC generated through site-specific conjugation of cleavable linkers and auristatin drug payloads with a drug-to-antibody ratio (DAR) of 4 dose-dependently inhibited the BxPc3 and KATO-III/hCLDN18.2 cells growth. (a,b) The target cells were incubated with varying concentrations of anti-CLDN18.2 cleavable ADC for 4 days. The cell viability was determined by luminescence by using CellTiter-Glo reagent (Promega). n = 3 technical replicates. NNC-Auristatin: anti-BHV-Auristatin. Bispecific and diabody also effectively eliminates BxPC3 or KATO-III/hCLDN18.2-Luc cells in a dose dependent manner. (c,d) Luciferase-labeled target cells were incubated with varying concentrations of the antibody and fixed ratio of Pan-T vs tumor cells (5:1) for 2 days. After 2 days of incubation, viability of BxPC3 or KATO-III cells were assessed using One-Glo luciferase assay reagent (Promega). The IC50s were then determined by nonlinear regression plot of percent specific cytotoxicity versus Log10 concentration of CLDN18.2 bispecific using GraphPad Prism software, Version 7.04. The results were shown as mean ± standard deviation (SD). αCD3-stumpy: CD3 variable and constant region combined with a truncated antibody consisting of only the hinge/constant region.
