SB-1295 is an orally active CDK9/T1 inhibitor ( IC 50 =0.17 μM). SB-1295 shows antiproliferative activity in HCT 116 and MIA PaCa-2 cells. SB-1295 also induces MIA PaCa-2 cell death by inducing intracellular ROS production, reducing mitochondrial membrane potential and inducing apoptosis. SB-1295 has the potential to study cancer.