(5P)-3-(carboxymethoxy)-4-chloro-5-(3-{[(4S)-1-({3-[2-(4-{3-[(3R)-2,6-dioxopiperidin-3-yl]-2-oxo-2,3-dihydro-1,3-benzoxazol-6-yl}piperidin-1-yl)acetamido]phenyl}methanesulfonyl)-2,2-dimethylpiperidin-4-yl]amino}phenyl)thiophene-2-carboxylic acid; ACETATE ION