Piper Jaffray analyst Steven Breazzano says Ultragenyx's risk/reward profile is favorable following the recent pullback in the shares. The analyst recommends buying the stock based on the blockbuster potential of KRN23 in adult and pediatric X-linked hypophosphatemia patients. After taking a closer look at Ultragenyx's UX007 Phase 2 program for both fatty acid oxidation disorders and Glut1 deficiency syndrome, the analyst sees a greater than 50% chance of success in both. He notes the program would represent "meaningful upside" to his model. He reiterates an Overweight rating on Ultragenyx with an $82 price target.