PROBLEM TO BE SOLVED: To provide a compound useful as an active ingredient of a therapeutic pharmaceutical composition for a disease involved in RANKL/RANK signals, such as osteoporosis, osteopenia and rheumatoid arthritis.SOLUTION: The prevent inventors have been studied about a compound having RANKL/RANK signal inhibitory activity, confirmed that a 2-(pyridine-2-yl) pyrimidine-4-amine compound or a salt thereof has potent RANKL/RANK signal inhibitory activity, improves RANKL-induced bone mineral density reduction and is effective in an osteoporosis model, and completed the present invention. The 2-(pyridine-2-yl) pyrimidine-4-amine compound or a salt thereof of the present invention has RANKL/RANK signal inhibitory activity and can be used as a therapeutic agent for a disease involved in RANKL/RANK signals, such as osteoporosis, osteopenia and rheumatoid arthritis.COPYRIGHT: (C)2015,JPO&INPIT【課題】骨粗鬆症、骨減少症、関節リウマチ等のRANKL/RANKシグナルが関与する疾患の治療用医薬組成物の有効成分として有用な化合物を提供する。【解決手段】本発明者らは、RANKL/RANKシグナル阻害活性を有する化合物について検討し、2-(ピリジン-2-イル)ピリミジン-4-アミン化合物又はその塩が強力なRANKL/RANKシグナル阻害活性を有すること、RANKL誘発骨塩量減少を改善すること及び骨粗鬆症モデルで有効であることを確認し、本発明を完成した。本発明の2-(ピリジン-2-イル)ピリミジン-4-アミン化合物又はその塩はRANKL/RANKシグナル阻害活性を有し、骨粗鬆症、骨減少症、関節リウマチ等のRANKL/RANKシグナルが関与する疾患の治療剤として使用しうる。【選択図】なし
