Avoralstat, a small molecule inhibitor of plasma kallikrein, participated in clinical trials phase III to prevent hereditary angioedema, but these studied were discontinued due to insufficient efficacy study. Recently published article has described that avoralstat could improve the quality of life in C1‐INH‐HAE patients. Hereditary angioedema (HAE) with C1 inhibitor deficiency (C1‐INH‐HAE) is an autosomal dominant disorder characterized by recurrent episodes of swelling of the skin, pharynx, gastrointestinal tract, genitals, and is due primarily to mutations in the SERPING1 gene that results in insufficient production of the natural plasma kallikrein inhibitor, C1 inhibitor (C1‐INH).