ARN-21934 display a different affinity for topoIIα and topoIIβ. ARN-21934 is more potent against the α isoform, the IC50 value for the inhibition of DNA relaxation by topoIIα is 2 μM, the value for inhibition of DNA relaxation by topoIIβ is 120 μM.
ARN-21934 exhibits a small panel of human cancer cell lines. It against melanoma (A375 and G-361), breast (MCF7), endometrial (HeLa), lung (A549), and androgen-independent prostate (DU145) cancer cells with IC50 values of 12.6 μM, 8.1 μM, 15.8 μM, 38.2 μM, 17.1 μM, and 11.5 μM, respectively.