Provided herein are antibodies that immunospecifically bind to CD123. Also described are related polynucleotides capable of encoding the provided CD123-specific antibodies or antigen-binding fragments, cells expressing the provided antibodies or antigen-binding fragments, as well as associated vectors and detectably labeled antibodies or antigen-binding fragments. In addition, methods of using the provided antibodies are described. For example, the provided antibodies may be used to diagnose, treat, or monitor CD123-expressing cancer progression, regression, or stability； to determine whether or not a patient should be treated for cancer； or to determine whether or not a subject is afflicted with CD123-expressing cancer and thus may be amenable to treatment with a CD123-specific anti-cancer therapeutic, such as the multispecific antibodies against CD123 and CD3 described herein.本文中提供免疫特異性結合至CD123之抗體。亦描述能夠編碼所提供之CD123特異性抗體或抗原結合片段的相關多核苷酸、表現所提供之抗體或抗原結合片段的細胞、以及相關聯之載體和經可偵測標示之抗體或抗原結合片段。此外，描述使用所提供抗體之方法。舉例而言，所提供抗體可用來診斷、治療或監測CD123表現性癌症之進展、消退、或穩定；從而判定病患是否應該進行癌症治療；或者判定對象是否患有CD123表現性癌症並因而可用CD123特異性抗癌症治療劑諸如本文中所述之針對CD123及CD3的多特異性抗體來進行治療。
