Ionis Pharmaceuticals won FDA approval for a drug that prevents painful swelling attacks triggered by a rare genetic condition, hereditary angioedema.

On Thursday, the U.S. Food and Drug Administration (FDA) approved Ionis Pharmaceuticals, Inc.’s (NASDAQ:IONS) Dawnzera (donidalorsen) for prophylaxis to prevent attacks of hereditary angioedema (HAE) in adult and pediatric patients 12 years of age and older.