NOVEL HETEROATOM CONTAINING TETRACYCLIC DERIVATIVES AS SELECTIVE ESTROGEN RECEPTOR MODULATORS.

The present invention is directed to novel heteroatom containing tetracyclic derivatives, pharmaceuticalcompositions contianing them, their use in the treatment and/or prevention of disorders mediated by oneor more estrogen receptors and processes for their preparation. The compounds of the invention areuseful in the treatment and/or prevention of disorders associated with the depletion of estrogen such ashot flashes, vaginal dryness, osteopenia and osteoporosis hormone sensitive cancers and hyperplasia of the breast, endometrium, cervix and prostate endometriosis, uterine fibroids, osteoarthritis and as contraceptive agents, alone or in combination with a progestogen or progestogen antagonist.