IL-31

Class

anti-IL-31 neutralizing biologic ("Attobody")

Pathway

neutralizes IL-31, the principal cytokine driver of pruritus (itch) in atopic dermatitis

IL-31 is a signaling protein (cytokine) produced mainly by a subset of immune cells called Th2 lymphocytes, along with mast cells and other cells involved in allergic-type inflammation. It is widely regarded as the principal molecular trigger of itch in atopic dermatitis and related chronic itch conditions. IL-31 acts on a receptor complex found on sensory nerve endings in the skin, as well as on keratinocytes (skin surface cells) and immune cells, linking allergic inflammation directly to the itch sensation. Because chronic scratching in atopic dermatitis worsens skin barrier damage and perpetuates a cycle of inflammation and itch, interrupting this cytokine's activity offers a way to break that cycle at its source rather than only treating downstream inflammation or barrier repair. A neutralizing biologic works by binding circulating IL-31 and preventing it from engaging its receptor, effectively removing the signal before it reaches nerve cells. This approach is relevant across atopic dermatitis and other pruritic skin diseases where excessive IL-31 signaling is implicated, and it represents a targeted alternative to broader immunosuppressive strategies, aiming to reduce the disabling itch that drives much of the disease burden and quality-of-life impact in these conditions.