Rigosertib potassium (formerly also known as ON-01910), the sodium salt
of Rigosertib, is a novel, potent and non-ATP-competitive inhibitor of
PLK1 with IC50 of 9 nM in a cell-free assay. It shows 30-fold greater
selectivity against Plk2 and no activity to Plk3. Rigosertib can
be potentially used for the treatment of cancer. Rigosertib inhibits
polo-like kinase1 (Plk1), inducing selective G2/M arrest followed by
apoptosis in a variety of tumor cells while causing reversible cell
arrest at the G1 and G2 stage without apoptosis in normal cells. This
agent may exhibit synergistic antitumor activity in combination with
other chemotherapeutic agents.