IL-13 and IL-31

Class

anti-IL-13 x IL-31 bispecific biologic ("Attobody", half-life extended)

Pathway

simultaneously blocks IL-13 (Th2-driven inflammation) and IL-31 (neurogenic pruritus)

IL-13 and IL-31 are signaling proteins (cytokines) central to type 2 immune responses that underlie many allergic and itch-associated skin diseases. IL-13 is produced by T-helper type 2 (Th2) cells and drives chronic inflammation, tissue remodeling, and disruption of the skin barrier by engaging a receptor complex that activates the JAK-STAT6 signaling pathway, which in turn promotes further inflammatory mediator production and antibody class-switching to IgE. IL-31, in contrast, acts more directly on sensory nerve endings, engaging its own receptor to trigger neuronal signaling that produces the sensation of itch, largely independent of the surrounding inflammatory cascade. Because chronic pruritic skin diseases often have both an inflammatory component and a distinct neurogenic itch component that do not always resolve together, a single molecule capable of neutralizing both cytokines addresses two separate disease drivers rather than one, potentially achieving more complete symptom control than blocking either pathway alone. A bispecific biologic engineered for extended circulating half-life binds and inactivates both cytokines before they can engage their respective receptors. This dual mechanism is broadly relevant across chronic pruritic and Th2-driven inflammatory skin conditions, where uncoupling itch from inflammation has been a persistent clinical challenge.