rigosertib rigosertib rigosertib (on-01910 sodium salt, with estybon as trade name) is a synthetic benzyl styryl sulfone in development by onconova therapeutics. rigosertib is in phase iii clinical trials for the treatment of chronic myelomonocytic leukemia. rigosertib names iupac name (2-methoxy-5-phenyl)glycine systematic iupac name (2-methoxy-5-anilino)acetate other names on-01910 identifiers cas number 592542-59-1 y 3d model (jsmol) : interactive image chebi chebi:145417 chembl chembl1241855chembl2013119 chemspider 5293927 iuphar/bps 7833 kegg d10154 pubchem cid 6918736 unii 67dow7f9gl y comptox dashboard (epa) dtxsid30207984 inchi inchi=1s/c21h25no8s/c1-27-15-10-19(29-3)16(20(11-15)30-4)7-8-31(25,26)13-14-5-6-18(28-2)17(9-14)22-12-21(23)24/h5-11,22h,12-13h2,1-4h3,(h,23,24)/b8-7+key: owbfcjroiknmgd-bqyqjahwsa-n smiles : coc1=c(c=c(c=c1)cs(=o)(=o)/c=c/c2=c(c=c(c=c2oc)oc)oc)ncc(=o)o properties chemical formula c21h25no8s molar mass 451.49 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references its geometrical isomer (z)-on 01910·na has less cytotoxicity on cancer cells. mechanism rigosertib is a microtubule-destabilizing agent.