The present invention relates to salts, hydrates, and polymorphs of bicyclic heteroaryl compounds, and pharmaceutical compositions thereof, which may be useful as inhibitors of H4R for the treatment or prevention of diseases including allergic rhinitis.本發明係關於可用作用於治療或預防包括過敏性鼻炎之疾病之H4R抑制劑的雙環雜芳基化合物之鹽、水合物及多晶型物及其醫藥組合物。