Despite the heavy competition in psoriasis, AnaptysBio Inc. believes it can make a mark with a first-in-class antibody for a neglected, inherited form of pustular psoriasis caused by a loss-of-function mutation in the proinflammatory cytokine IL-36RA. The company plans to test the mAb in the Orphan indication where the clinical path is clear and there are few competitors, and is banking on the chance the compound can be expanded more broadly for general psoriasis.
AnaptysBio announced today its plans to develop the antibody - dubbed ANB019 - for generalized pustular psoriasis (GPP), an autosomal recessive form of psoriasis that manifests in pustular rashes and life-threatening organ involvement. Like psoriasis, GPP involves elevated levels of IL-36 and other inflammatory cytokines, as well as elevated numbers of T cells and neutrophils in inflamed tissues. However, the indication accounts for less than one in a thousand of all psoriasis cases.
In a normal immune response to bacterial or fungal infection, the three isoforms of IL-36 - IL-36α, IL-36β and IL-36γ - activate inflammatory T cells via the cytokine receptor IL-36R. IL-36RA serves as a natural antagonist of IL-36R and dampens the inflammatory effects