Piper Jaffray analyst David Amsellem says his survey of 25 rheumatologists who are current users of Horizon Pharma's Krystexxa in patients with chronic refractory gout reinforced his view that the rheumatology community's view of the risk/benefit profile of the product "continues to evolve considerably, pointing to greater usage among existing Krystexxa users." The feedback also bodes well for usage of the product among practices that are relatively new to Krystexxa, Amsellem tells investors in a research note. He continues to believe that the combination of "continued aggressive" Krystexxa growth along with contribution from teprotumumab starting next year points to a longer term annual EBITDA growth for Horizon "at least in the high-teens." Amsellem keeps an Overweight rating on the shares with a $33 price target.