CX-6258 shows antiproliferative activity against a panel of human cancer cell lines with IC50 of 0.02-3.7 μM, mostly sensitive to acute leukemia cell lines. Combinations of CX-6258 with doxorubicin (10:1 molar ratio) and CX-6258 with paclitaxel (100:1 molar ratio) produces synergistic cell killing with combination index (CI50) values equal to 0.4 and 0.56, respectively. CX-6258 causes dose dependent inhibition of the phosphorylation of two pro-survival proteins, Bad and 4E-BP1, at the Pim kinase specific sites S112 and S65 and T37/46, respectively.
In vivo
CX-6258 exhibits dose dependent efficacy in suppressing tumor growth in mice carrying MV-4-11 xenografts, with a 50 mg/kg dose producing 45% tumor growth inhibition (TGI) and a 100 mg/kg dose producing 75% TGI