In order to provide a wide range of tumors and cancer treatment and prevention measures, including PI3K / Akt pathway activation and p53 inactivated cancer and tumors where conventional therapies such as chemotherapy, radiation therapy and hormone therapy are less effective, OBP-801 and a PI3K inhibitor, preferably LY294002, BKM120, GDC-0941, BEZ235, BYL719, or CH5132799, are used in combination. Thereby, synergistic activation of caspase pathway, enhanced expression of Bim, increased accumulation of intracellular reactive oxygen species, and suppression of survivin and XIAP protein expression, which cannot be obtained by prescribing each molecular target drug alone It is possible to obtain a number of different remarkable pharmacological effects at the same time, and to provide clinically effective new tumor treatment and prevention strategies as effective therapeutic and preventive drugs applicable to a wide range of tumors. Become.ＰＩ３Ｋ／Ａｋｔ経路の活性化やｐ５３が失活した癌や、化学療法、放射線療法及びホルモン療法などの従来療法の有効性が低い腫瘍を含む幅広い腫瘍や癌の治療及び予防手段を提供するため、ＯＢＰ－８０１と、ＰＩ３Ｋ阻害剤、好適にはＬＹ２９４００２、ＢＫＭ１２０、ＧＤＣ－０９４１、ＢＥＺ２３５、ＢＹＬ７１９又はＣＨ５１３２７９９という、異なる分子標的薬を併用する。それにより、各分子標的薬単剤の処方では得ることができない、相乗的な、カスパーゼ経路の活性化、Ｂｉｍの発現増強、細胞内活性酸素種の蓄積増加、並びに、サバイビン及びＸＩＡＰタンパク質の発現抑制という複数の異なる顕著な薬理効果を同時に得ることが可能となり、幅広い腫瘍に適用できる有効な治療薬及び予防薬として、臨床的に有効な新たな腫瘍の治療・予防戦略を提供することが可能となる。
