Substantially optically pure (S)-trans-{4-[({2-[({1-[3,5-bis(trifluoromethyl)phenyl]ethyl}{5-[2-(methylsulfonyl)ethoxy]pyrimidin-2-yl}amino)methyl]-4-(trifluoromethyl)phenyl}(ethyl)amino)methyl]cyclohexyl}acetic acid, or a salt thereof, or a solvate thereof, which has actions of reducing amount of PCSK9 protein and increasing amount of LDL receptor.PCSK9 단백량을 저하시켜 LDL 수용체량을 증가시키는 작용을 갖는 실질적으로 광학적으로 순수한 (S)-트랜스-{4-[({2-[({1-[3,5-비스(트리플루오로메틸)페닐]에틸}{5-[2-(메틸술포닐)에톡시]피리미딘-2-일}아미노)메틸]-4-(트리플루오로메틸)페닐}(에틸)아미노)메틸]시클로헥실}아세트산 또는 그의 염, 또는 그들의 용매화물.