Sienna Biopharmaceuticals, Inc. was a clinical-stage biopharmaceutical firm dedicated to discovering and advancing pharmaceutical treatments across diverse therapeutic fields. Its primary focus involved crafting therapies within immunology and inflammation, specifically targeting particular tissue pathways, notably in the skin. Among its pipeline, SNA-120 stood out as a pioneering, first-in-class inhibitor of tropomyosin receptor kinase A, undergoing Phase IIb clinical evaluation for addressing psoriasis and its associated itching.