What is "alestramustine"

Alestramustine ( INN), also known as estradiol 3-(bis(2-chloroethyl)carbamate), 17-ester with L-alanine, is a nitrogen mustard alkylating antineoplastic drug that was never marketed. It is the L-alanine ester of estramustine, which is a combination of the nitrogen mustard normustine coupled via a carbamate to the estrogen estradiol. Alestramustine acts as a prodrug to estramustine, and also forms estradiol as a byproduct. The drug, via its active metabolites, binds to microtubule-associated proteins and β-tubulin and interferes with microtubule function, thereby inhibiting cell division. Due to its estrogen moiety, alestramustine is selectively concentrated in estrogen receptor-positive cells such as prostate and breast.