Novel class of non-steroidal progesterone receptor antagonists

Development of antiprogestins as a new class of therapeutic agents has been of great interest to the pharmaceutical industry for decades. Currently, all clinically available antiprogestins are compounds with a steroidal skeleton. The new generation of non-steroidal antiprogestins is very promising but still in its infancy. This review summaries the recent progress in the area of non-steroidal progesterone receptor antagonists. These antiprogestitional compounds, derived from cyclocymopols, dihydroquinolines, pyridazines, linear tricyclic sesquiterpenes and vitamin D derivatives, have been proposed to be used as contraceptive agents, abortifacients and for use in hormone replacement therapy, as well as for use in the treatment of endometriosis, osteoporosis and progesterone responsive cancers of the ovary, breast and prostate.