Supinoxin

Supinoxin (RX-5902) is an orally active inhibitor of phosphorylated-p68 RNA helicase (P-p68) and a potent first-in-class anti-cancer agent. Supinoxin interacts with Y593 phosphorylated-p68 and attenuates the nuclear shuttling of β-catenin. Supinoxin induces cell apoptosis and inhibits growth of TNBC cancer cell lines with IC₅₀s ranging from 10 nM to 20 nM^[1][2]. IC50 & Target: IC50: phosphorylated-p68 RNA helicase; apoptosis^[1] In Vitro: RX-5902 (0-10 μM; 72 hours) is active against cell lines of all TNBC molecular subtypes and is active against cell lines with mutations in p53, RB1, CDKN2A, and loss of PTEN^[1].
RX-5902 (20-100 nM; 24 hours) treatment results in a dose-dependent increase in tetraploid cells, consistent with induction of G2–M cell-cycle arrest^[1].
RX-5902 (0-100 nM; 72 hours) exhibits no significant induction of apoptosis in cell lines resistant to the antiproliferative effects of RX5902. But in sensitive cells, the observed activation of apoptosis begins at 24–48 hours and reaches a peak at 72 hours. The induced apoptosis is greasted with a dose of 100 nM^[1].
RX-5902 (0-100 nM; 24 or 48 hours) decreases MCL-1 expression as a dose-dependent manner in TNBC cell lines sensitive to RX-5902^[1].
RX-5902 inhibits cell growth, MDA-MB-231, Caki-1, UMRC2, PANC-1, A549, MKN-45, HepG2, HCT116, HT29, PC-3, U251, HeLa, SK-MEL-28 and OVCAR-3 with IC₅₀ values range from 0.01 μM to 0.021 μM in the growth inhibition of cancer cells^[2].
In Vivo: RX-5902 (oral administration; 160/320/600 mg/kg; once weekly for 3 weeks) significant dose-dependent tumor growth inhibition (TGI) in the MDA-MB-231 model, exhibits TGI of 55.7%, 80.29% and 94.58% at 160 mg/kg, 320 mg/kg and 600 mg/kg, respectively. It is more efficacious than the chemotherapy control arm of nab-paclitaxel (TGI 45%)^[1].