The present invention relates to: - use of a 2,3-dihydroimidazo[1,2-c]quinazoline compound, or of a pharmaceutical composition containing same, as a sole active agent, or of a combination of a) said compound or a pharmaceutical composition containing said compound and b) one or more further active agents, for the preparation of a medicament for the treatment or prophylaxis of cancer - combinations of a) said compound and b) one or more further active agents - a pharmaceutical composition comprising said compound as a sole active agent for the treatment of breast cancer - a pharmaceutical composition comprising a combination of a) said compound and b) one or more further active agents - use of biomarkers involved in the modification of Bel expression, HER family expression and/or activation, PIK3CA signaling and / or loss of PTEN for predicting the sensitivity and /or resistance of a cancer patient to said compound and providing a rationale-based synergistic combination as defined herein to increase sensitivity and/or to overcome resistance and - a method of determining the level of a component of one or more of Bcl expression, HER family expression and/or activation, PIK3CA signaling and / or loss of PTEN.La présente invention concerne lutilisation dun composé de 2,3-dihydroimidazo[1,2-c]quinazoline ou dune composition pharmaceutique contenant ce composé en tant quagent actif unique, ou dune combinaison a) dudit composé ou dune composition pharmaceutique contenant ledit composé et b) dun ou de plusieurs agents actifs, pour la préparation dun médicament dans le traitement ou la prophylaxie du cancer. Linvention porte également sur des combinaisons a) dudit composé et b) dun ou de plusieurs agents actifs. Linvention a également trait à une composition pharmaceutique comprenant ledit composé en tant quagent actif unique dans le traitement du cancer de la poitrine, et à une composition pharmaceutique comprenant une combinaison a) dudit composé et b) dun ou de plusieurs
