Partial tumor growth suppression occurs with either Epothilone B (Patupilone) or ionizing radiation treatment alone over ten days. However, their combined application significantly enhances tumor growth control, resulting in complete tumor regression during the follow-up period (P<0.005 for either treatment alone versus combined treatment)^[3].

Epothilone B is a microtubule stabilizer with a Ki of 0.71μM, which acts by binding to the αβ-tubulin heterodimer subunit which causes decreasing of αβ-tubulin dissociation^[1].

Epothilone B displays potent cytotoxic activity against HCT116 cells, with an IC50 value of 0.8 nM in a cytotoxicity assay^[1].

As a microtubule-targeting compound, Epothilone B (Patupilone) effectively hinders cell proliferation, evidenced by an IC50 of 6 nM in MTT cell proliferation assays after 72 hours of treatment. Concentrations of Epothilone B ≤1 nM do not exhibit cytotoxic effects. At a non-toxic concentration of 1 nM, Epothilone B significantly curtails transwell cell migration, with an increased effect observed at 10 nM^[2].

In human medulloblastoma cell lines, Epothilone B (Patupilone) acts as a novel, non-taxane microtubule stabilizer without neurotoxic effects. It diminishes proliferative activity in D341, D425Med, and DAOY cell lines with IC50 values of 0.53 nM, 0.37 nM, and 0.19 nM, respectively. The impact on clonogenic survival in the D341Med cell line mirrors the effects on proliferative activity (IC50, 0.50-0.75 nM), whereas D425Med and DAOY cell clonogenicity significantly drops at ten times lower Epothilone B concentrations (IC50, 30 pM), showcasing its high efficacy against various medulloblastoma cell lines^[3].