PN-881

PN-881 is a synthetic oral peptide antagonist of interleukin-17 (IL-17), developed by Protagonist Therapeutics for the treatment of immune-mediated skin diseases and other IL-17-driven conditions. It demonstrates high potency in blocking all three therapeutically relevant dimeric forms of IL-17 (AA homodimer, FF homodimer, and AF heterodimer), with approximately 100-fold greater efficacy than secukinumab and comparable potency to leading injectable antibody drugs and nanobody therapeutics. Preclinical studies have shown effective blockade of IL-17 in serum and skin, as well as proof-of-concept efficacy in rodent models of skin inflammation. IND-enabling studies are underway, with Phase 1 clinical trials planned to begin in late 2025. Primary indications under development include psoriasis, psoriatic arthritis, hidradenitis suppurativa, and axial spondyloarthropathies[1][2][3][4][5].