Ionis Pharmaceuticals won U.S. regulatory clearance for Dawnzera, the company’s first wholly owned commercial product, giving patients with hereditary angioedema a new option to prevent the painful swelling episodes that characterise the rare genetic disorder. The antisense medicine, chemically known as donidalorsen, lowers levels of prekallikrein, a protein that drives inflammation. In a 24-week late-stage trial, patients dosed once every four weeks experienced an 81% drop in monthly attacks versus placebo. Dawnzera can be self-injected under the skin every four or eight weeks and is approved for adults and adolescents aged 12 and older. Ionis set a U.S. list price of $57,462 per dose and said the drug will reach the market within days. The company enters a market currently led by Takeda’s Takhzyro and CSL Behring’s Haegarda; TD Cowen projects Dawnzera could generate about $509 million in annual sales by 2032. Roughly 7,000 people in the United States are estimated to live with hereditary angioedema.