1125 GMT - Argenx's decision to stop a late-stage clinical trial of its Vyvgart drug in Sjogren's disease comes as a major negative surprise for the European biotech company, UBS analysts say in a note. "We believe Argenx's discontinuation of Sjogren's study at interim suggests potentially very little efficacy--if any--not just a 'near miss'," the analysts say. The drug had generated positive and solid results in a midstage study, as had a similar medicine from rival Johnson & Johnson, Imaavy, they add. The study was supposed to be one of the most closely watched updates from Argenx next year, and UBS had modeled peak annual sales for Vyvgart in Sjogren's at $3.5 billion, the analysts say. Shares fall 16%.