2-Methoxyestradiol disulfamate
2-Methoxyestradiol disulfamate, or 2-methoxyestradiol 3,17β-O,O-bis, is a synthetic, oral active anti-cancer medication which was previously under development for potential clinical use. It has improved potency, low metabolism, and good pharmacokinetic properties relative to 2-methoxyestradiol. It is also a potent inhibitor of steroid sulfatase, the enzyme that catalyzes the desulfation of steroids such as estrone sulfate and dehydroepiandrosterone sulfate.
STX-140 exhibits anti-angiogenic activity and induction of cell cycle arrest and apoptosis in human tumor xenografts, with clinical potential for hormone–independent tumors. Some of this activity stems from tubulin binding at the colchicine site and disruption of interphase microtubules. STX-140 is highly active in tumors that are resistant to chemotherapy.
In xenograft models of breast and prostate cancer complete cures were achieved after oral treatment with STX-140 and drug-resistant tumors also shrank in size after oral treatment. Conventional treatments for hormone-independent cancers targeting tubulin are associated with side effects, such as neurotoxicity, and can only be given infrequently and intravenously. STX-140 is more effective on the same tumors, blocks metastatic spread without the peripheral neuropathy associated with current clinical anticancer drugs.
