The present invention relates to combinations of at least two components, component A and component B, component A being an inhibitor of PI3K kinase, and component B being radium 223, particularly a pharmaceutically acceptable salt of radium-223. Another aspect of the present invention relates to the use of such combinations as described herein for the preparation of a medicament for the treatment or prophylaxis of a disease, particurlarly for the treatment of breast and prostate cancer as well as their bone metatases.