The Novato, California-based biotech Ultragenyx yesterday announced, before Wall Street opened, that its investigational therapy Crysvita (burosumab) has obtained the FDA approval for the treatment of X–Linked Hypophosphatemia (XLH), a rare condition. XLH is a serious disease affecting bones, which become fragile and softer due to a reduction in phosphate reabsorption and vitamin D production. It affects 12,000 people in the US. This is the second FDA approval to a therapy by Ultragenyx; MEPSEVII™ (vestronidase alfa), the first treatment ever for the rare disease mucopolysaccharidosis VII–was approved last November. Crysvita will be launched at $200,000 per treatment for adult patients and $160,000 for children. Ultragenyx’s shares yesterday increased approximately 2% (Nasdaq).