Ionis Pharmaceuticals is trading 12.55% down at $50.80, after closing at $58.09 on September 4, 2026; the decline follows FDA approval of ZANVASTRO for Alexander disease, though coverage does not establish approval caused the selloff.

  • Reuters confirmed the approval as a major positive milestone.
  • Investors remain focused on launch execution and reliance on late-stage programs.
  • Potential pricing pressure and valuation uncertainty remain concerns.