Riviciclib is a potent inhibitor of cyclin-dependent kinase (CDK)(CDK9-cyclinT1, CDK4-cyclin D1, and CDK1-cyclinB with IC50s of 20 nM, 63 nM, and 79 nM, respectively),with antitumor activity on cisplatin-resistant cells.

CDK4-CyclinD1:0.063 μM, CDK2-CyclinE:2.540 μM, CDK6-CyclinD1:0.396 μM, CDK1-CyclinB:0.079 μM, CDK2-CyclinA:0.224 μM, CDK9-CyclinH:2.900 μM, CDK9-CyclinT1:0.020 μM

Riviciclib (3-24 hours; 1.5 μM) reduces cyclin D1, Cdk4, and Rb levels in H-460 cells. Rb (retinoblastoma) phosphorylation at Ser780 decrease at 3 h. Riviciclib shows activity in human cancer cell lines, such as colon carcinoma, osteosarcomal, cervical carcinoma, and bladder carcinoma cells[2].Riviciclib shows no detectable cells in G1 and G2 in promyelocytic leukemia cells and arrest of cells in G1 in synchronized human non-small cell lung carcinoma (H-460) and human normal lung fibroblast (WI-38) cells[3].

Riviciclib in human xenograft mode with severe combined immunodeficient mice shows significant inhibition in the growth of human colon carcinoma HCT-116 xenograft[3].