A medicinal composition for preventing or treating secondary hyperparathyroidism under maintenance dialysis, said medicinal composition comprising 3-{[(2S)-2-amino-2-carboxyethyl]carmaboylamino}-5-chloro-4-methylbenzenesulfonic acid or a pharmaceutically acceptable salt thereof, or a solvate of the same which is to be administered by a predefined route in a predefined dosage. According to the present invention, it is possible to provide a prophylactic or therapeutic agent for secondary hyperparathyroidism under maintenance dialysis, said agent showing reduced side effects or no significant accumulation. This medicinal agent allows easy administration management and has a high safety compared with conventional products.本發明與一種維持透析下之二次性副甲狀腺機能亢進症之預防或治療用醫藥組成物有關，其按照預定之用法．用量投與3-{[(2S)-2-胺基-2-丙烯酸羧乙酯]胺甲醯胺基}-5-氯-4-甲基苯磺酸或其在製藥學上所容許之鹽或者是此等之溶劑合物。藉由本發明，可提供一種減低副作用，或者是不表現明顯累積性之維持透析下之二次性副甲狀腺機能亢進症之預防或治療用醫藥組成物，且為投與管理比傳統製品容易，較安全之藥劑。
