MDNA209

MDNA209 is a first-in-class, beta-enhanced interleukin-2 (IL-2) super-antagonist developed by Medicenna Therapeutics for the potential treatment of autoimmune diseases and graft-versus-host disease (GvHD)[1][3][5][6]. It is an engineered protein (Superkine™) with approximately 200 times higher affinity for the IL-2 receptor beta subunit (IL-2Rβ), selectively blocking the IL-2Rβγc complex without engaging the gamma c subunit[4][6]. This mechanism allows it to act as a "receptor clamp," preventing native IL-2 and interleukin 15 (IL-15) from activating effector CD8+ T cells that drive tissue damage in autoimmune conditions[6]. Preclinical studies have shown that MDNA209 can restore immune balance by inhibiting both IL-2 and IL-15-induced signaling pathways, reducing inflammatory cytokine release and immune cell proliferation while sparing regulatory T cells. In animal models of acute GvHD, it extended survival by 400%, reduced weight loss, and improved clinical scores[5][6][10]. The molecule is fused to an Fc scaffold to extend its half-life in vivo. As of June 2025, development remains at the preclinical/discovery stage.

Other names

IL-2 Super-antagonistIL2 Super-antagonistIL 2 Super-antagonistbeta-enhanced IL-2 Super-antagonist