HETEROCYCLIC SILICON COMPOUNDS AND THEIR USE IN THE TREATMENT OF DISEASES OR CONDITIONS ASSOCIATED WITH GNRH (GONADOTROPIN-RELEASING HORMONE)

A compound of formula (I) wherein one of X and Y is silicon, and the other i s carbon or silicon Z is oxygen, sulphur or -N(R)-, wherein R is hydrogen or alkyl R1 is hydrogen, halogen, alkyl, alkenyl, alkynyl, alkoxy or cycloalky l and R2 is alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, -alkyl-cycloalkyl, -alkyl-heterocycloalkyl, -alkyl-aryl or -alky l- heteroaryl or a pharmaceutically acceptable salt thereof. The compounds are used in the manufacture of a medicament for the treatment or prevention of a disease or condition associated with GnRH (gonadotropin-releasing hormone), e.g. for the treatment or prevention of progression of cancer (e.g. leukaemi a therapy), of a fertility disorder, of HIV infection or AIDS, of Alzheimer~s disease of fibrosis, of endometriosis, of uterine fibroids or of uterine leiomyoma.