New interim data from Ultragenyx Pharmaceutical Inc. and Genetx Biotherapeutics LLC’s phase I/II study of GTX-102 in Angelman’s syndrome didn’t do much to bolster investor confidence, as Ultragenyx shares sagged considerably July 19. The Novato, Calif.-based company’s stock (NADAQ:RARE) closed 13% downward at $52.89 per share. That is nearly half the price shares fetched in late August. At $102.40 per share, that was the stock’s highest value in the past 12 months.