Tirbanibulin is an inhibitor of Src that targets the peptide substrate site of Src (GI50: 9-60 nM in cancer cell lines).

Src (Hep3B):26 nM, Src (HuH-7):(GI50)9 nM, Src (HepG2):60 nM, Src (PLC/PRF/5):13 nM

Tirbanibulin (KX2-391) is found to inhibit certain leukemia cells that are resistant to current commercially available drugs, such as those derived from chronic leukemia cells with the T3151 mutation. KX2-391 displays steep dose-response curves against Huh7 (GI50=9 nM), PLC/PRF/5 (GI50=13 nM), Hep3B (GI50=26 nM), and HepG2 (GI50=60 nM), four hepatic cell cancer (HCC) cell lines[1]. Tirbanibulin is evaluated in engineered Src driven cell growth assays inNIH3T3/c-Src527F and SYF/c-Src527F cells and exhibits GI50 with 23 nM and 39 nM, respectively[2].

In pre-clinical animal models of cancer, Tirbanibulin (p.o.) is shown to inhibit primary tumor growth and to suppress metastasis[2].