AK139

AK139 is a first-in-class bispecific antibody developed by Akeso and Zhongshan Kangfang Biomedical that simultaneously targets interleukin-4 receptor alpha (IL-4Rα) and suppression of tumorigenicity 2 (ST2), the receptor for interleukin-33 (IL-33). By binding to both IL-4Rα and ST2, AK139 blocks key inflammatory signaling pathways mediated by IL-4, IL-13, and IL-33. This dual-target mechanism is designed to modulate T-helper 2 (Th2)-mediated immune responses as well as broader inflammatory processes implicated in respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD), dermatological conditions, anaphylaxis, and other disorders where these cytokines play a central role. Preclinical studies have demonstrated that AK139 exhibits strong synergistic effects between its two targets—outperforming single-target antibodies in reducing inflammatory cytokine release and tissue infiltration by immune cells. The drug is administered subcutaneously. As of early 2025, it has entered phase I clinical trials for respiratory tract disorders including asthma and COPD[1][3][6][7][9].

Other names

IL-4Rα/ST2 bispecific antibody