Construction of paclitaxel-based antibody–drug conjugates with a PEGylated linker to achieve superior therapeutic index

摘要

a Molecular structures of VC (Val–Cit-PAB) linker, VK (Val-Lys-PAB) linker, and hRS7-VK-PTX. b Reverse-phase (RP) HPLC analysis of the drug-to-antibody ratios (DARs) in different ADC molecules. hRS7:L0 + H0. ADC with DAR8:L1 + H3. c ADC molecules suppressed the growth of COLO205 cell-derived tumor xenografts. Two-tailed t test was used to assess statistical significance between treatment and control groups. ***P < 0.001, comparing hRS7-VK-PTX with hRS7; ⊳⊳⊳P < 0.001, comparing hRS7-VK-PTX with hRS7-VK-SN38 (n = 6 per group). Data = mean ± SD. d Dose-tolerability assay on hRS7-VK-PTX in BALB/c mice. e Treatment with both hRS7-VK-PTX and hRS7-VK-MMAE resulted in “bystander killing”, but hRS7-VK-PTX is more Trop-2-specific than hRS7-VK-MMAE (n = 5 per group). Data = mean ± SD. Right panel: schematic representation of “bystander killing” assay in mice. f Trafficking and cellular localization of anti-Trop-2 ADCs under confocal microscopy. Marker proteins LAMP-1, GM130, and clathrin (Red); anti-Trop-2 ADCs (Green); nuclear DNA (Blue). g ADC hRS7-VK-PTX internalized faster on MDA-MB-231 and CFPAC-1 cells analyzed by flow cytometry. h The suppression potency of free payload PTX and hRS7-VK-PTX on carcinoma cells with different Trop-2 expression levels