Piper Jaffray analyst Edward Tenthoff noted that Alnylam reported Q1 Onpattro sales of $26M, which beat his $14M estimate and the consensus forecast of $19M. Despite the Onpattro sales beat and trends that he said underscore the drug's "best-in-class profile," Tenthoff said the stock is reacting negatively to management having increased their 2019 expense guidance. The analyst, who raised his 2019 Onpattro sales forecast to $127M from $82M, keeps an Overweight rating and $142 price target on Alnylam. Near 11 am ET, Alnylam shares are down 4% to $85.49.