Discovery of 7-Methoxy-6-[4-(4-Methyl-1,3-Thiazol-2-yl)-1H-Imidazol-5-yl]-1,3-Benzothiazole (TASP0382088): A Potent and Selective Transforming Growth Factor-β Type I Receptor Inhibitor as a Topical Drug for Alopecia

The study synthesized and evaluated 7-Methoxy-6-[4-(4-methyl-1,3-thiazol-2-yl)-1H-imidazol-5-yl]-1,3-benzothiazole (TASP0382088) as a potent and selective inhibitor of the transforming growth factor-β (TGF-β) type I receptor (ALK5). Compound 11 demonstrated strong enzyme inhibitory activity with an IC50 of 4.8 nM and effectively inhibited TGF-β-induced Smad2/3 phosphorylation at the cellular level with an IC50 of 17 nM. Modifications to the compound improved its solubility in a lotion base. Topical application of a 3% lotion of compound 11 significantly inhibited Smad2 phosphorylation in mouse skin by 71% at 8 hours post-application, compared to vehicle-treated controls, indicating its potential as a topical treatment for alopecia.