The Adcom effectively negates the FDA priority review that the Amarin/Vascepa sNDA initially received. The initial PDUFA date was end of September 2019 for FDA to announce decision on expanded label. Standard review would have been January 2020. The Adcom won't be until November 14 at the earliest, and Amarin is now expecting a revised PDUFA date of late December 2019. The market doesn't like bad surprises, delays or uncertainty.
Good Stat news article on this. And here's the Amarin news release.