Synthesis and Purification of T3 and T3-1 Compounds

[4-(2-methyl-1-(4-methylpiperazin-1-yl)-1-oxopropan-2-yl)-N-(6-(pyridin-4-yl)imidazo [1,2-a]pyridin-2-yl)benzamide] (T3) was synthesised and purified as described previously [15 (link)]. [N-(8-fluoro-6-(pyridin-4-yl)imidazo[1,2-a]pyridin-2-yl)-4-(2-methyl-1-(4- methylpiperazin-1-yl)-1-oxopropan-2-yl)benzamide trihydrochloride] (T3-1) was synthesised and purified as shown in Supporting Information (S1 File). The Bcl-2 family protein inhibitor ABT-263 was purchased from MedChemExpress (HY-10087; Monmouth Junction, NJ, USA). The pan-caspase inhibitor Z-VAD-FMK was purchased from R&D Systems (FMK001; Minneapolis, MN, USA) and used at 25 μM in all the experiments described in the present study.