PROBLEM TO BE SOLVED: To provide a compound having mPGES-1 inhibition activity and useful for prevention or treatment of pain, rheumatism, osteoarthritis, fever, Alzheimer disease, multiple sclerosis, arteriosclerosis, glaucoma, ocular hypertension, ischemic retinal disease, systemic scleroderma and/or malignant tumor such as colon cancer.SOLUTION: There is provided a triazine compound represented by formulae [I-a], [I-b] or [I-c] or a pharmaceutically acceptable salt thereof. In the formulae [I-a] [I-b] [I-c], Ris methyl substituted by Calkyl or Ccycloalkane, Rand Rare each independently H or the like, Ris an isopropyl or the like, Ris Calkyl, Ris Calkyl or the like and X is CHor O.SELECTED DRAWING: None【課題】mPGES-1阻害活性を有し、疼痛、リウマチ、変形性関節症、発熱、アルツハイマー病、多発性硬化症、動脈硬化、緑内障、高眼圧症、虚血性網膜疾患、全身性強皮症及び／又は大腸癌をはじめとする悪性腫瘍の予防又は治療のために有用な化合物を提供する。【解決手段】式［I-a］、［I-b］若しくは［I-c］で表わされるトリアジン化合物、又はその薬学上許容される塩。［Ｒ１はＣ１－４アルキルで又はＣ３－７のシクロアルカン置換されたメチル；Ｒ２及びＲ３は各々独立にＨ等；Ｒ４は、イソプロピル等；Ｒ５は、Ｃ１－６アルキル；Ｒ６は、Ｃ１－６アルキル等；Ｘは、ＣＨ２又はＯである］【選択図】なし
