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 Bcl 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.本發明係關於：- 2,3-二氫咪唑并[1,2-c]喹唑啉化合物、或含有其作為唯一活性藥劑之醫藥組合物、或a)該化合物或含有該化合物之醫藥組合物與b)一或多種其他活性藥劑之組合的用途，其係用於製備用以治療或預防癌症之藥劑；- a)該化合物與b)一或多種其他活性藥劑之組合；-包含該化合物作為唯一活性藥劑用於治療乳癌之醫藥組合物；-包含a)該化合物與b)一或多種其他活性藥劑之組合之醫藥組合物；-與Bcl表現、HER家族表現及/或激活、PIK3CA信號傳導及/或PTEN損失之改變有關之生物標記之用途，其係用於預測癌症患者對該化合物之敏感性及/或抗性並提供如本文所定義之基於原理之增效組合，以增加敏感性及/或克服抗性；及-測定Bcl表現、HER家族表現及/或激活、PIK3CA信號傳導及/或PTEN損失中之一或多者之組份含量的方法。
