Described herein are amorphous and crystalline forms of pharmaceutically acceptable salts of the estrogen receptor modulator (E)-3-(4-((E)-2-(2-chloro-4-fluorophenyl)-1-(1H-indazol-5-yl)but-1-en-1-yl) phenyl)acrylic acid. Also described are pharmaceutical compositions suitable for administration to a mammal that include the estrogen receptor modulator, and methods of using the estrogen receptor modulator, alone and in combination with other compounds, for treating diseases or conditions that are associated with estrogen receptor activity.
