William Blair analyst Y. Katherine Xu upgraded Vital Therapies to Outperform from Market Perform and raised her fair value estimate for the shares to $35 from $10. Top-line data from the pivotal VTL-308 study of the company's Elad, or extracorporeal liver-assist device, versus standard of care in severe acute alcoholic hepatitis is expected in September, Xu tells investors in a research note. The analyst views the readout as a key binary event for both Vital Therapies shares and the acute liver failure field. She raised her probability of success of VTL-308 to 70% from 55% and upped her global peak sales estimate to $1.5B from $850M for Elad. VTL-308's primary endpoint is overall survival, and should the study be successful, it is highly likely that Elad becomes the standard of care for this population of patients over time, Xu contends.