The U.S. Food and Drug Administration on Thursday approved Ionis Pharmaceuticals’ Dawnzera, making it the first RNA-targeted medicine cleared to prevent hereditary angioedema attacks in patients aged 12 and older. The decision gives the California-based company its second independently marketed product in less than a year. Dawnzera, chemically known as donidalorsen, is self-administered as a subcutaneous injection once every four or eight weeks. In a Phase 3 study, the every-four-week regimen cut monthly swelling attacks by 81% compared with placebo over 24 weeks. The approved label carries a warning for potential anaphylaxis after a small number of hypersensitivity cases were observed in an open-label trial. Ionis set a U.S. list price of $57,462 per dose and expects to begin shipping the drug within days. The company is targeting an estimated domestic market of about 7,000 patients and will compete with existing prophylactic treatments such as Takeda’s Takhzyro, CSL Behring’s Haegarda and BioCryst’s oral therapy Orladeyo.