PROBLEM TO BE SOLVED: To provide compounds useful in the treatment of disorders or diseases mediated by the activity of MDM (murine double minute)2 and/or MDM4 that, in cancers, inhibit(s) the activity of tumor suppressor protein p53, inhibit(s) apoptosis of cells, and can cause uncontrolled tumor growth.SOLUTION: This invention relates to a method for administering imidazopyrrolidinone compounds expressed by the following formula and/or its crystalline polymorph in the treatment of disorders or diseases.SELECTED DRAWING: None【課題】癌等において、腫瘍サプレッサ蛋白質p53の活性を阻外し、細胞のアポトーシスを阻外し、無制限腫瘍増殖を可能にするMDM(マウスダブルミヌーテ)2及び/又はMDM4の活性によって媒介される障害又は疾患の治療に有効な化合物の提供。【解決手段】下記式にて例示されるイミダゾピロリジノン化合物及び/又はその結晶多形を前記障害又は疾患の治療に投与する方法。【選択図】なし