Novel enzyme inhibitors for treatment of breast cancer combine the inhibition of enzymes that combat aggressive breast cell growth both synergistically and additively. Pyrido-annulated indoles developed act in a selectively inhibiting manner on the enzymes HER2 and/or Brk in the nanomolar to picomolar concentration range in screening more than 200 kinases of the human kinome. The enzyme inhibitors inhibit the growth of breast cancer cells in the nanomolar concentration range without exhibiting critical toxic effects. The derivatization at the 6-position of the 4-chloro-α-carboline is achieved without by-products and, similarly to the derivatization at the 4-position with the aniline derivatives, takes place at high purity with quantitative yields.
