The invention relates to 6-alkylidenandrosta-1,4-diene-3,17-dione derivatives, having the following general formula ##STR1## wherein each of R and R.sub.2, independently, is hydrogen or C.sub.1 -C.sub.6 alkyl and R.sub.1 is hydrogen, halogen or C.sub.1 -C.sub.6 alkyl, which are useful in therapy, in particular in the treatment of hormone-dependent cancers.