Morgan Stanley analyst Matthew Harrison noted that IMS announced that it has overstated the mail order volume for Amgen's Aimovig and will amend its mail order method with this week's data and restate prior weeks next Friday. Preliminary figures indicate the restatement will lower overall total prescriptions by about 27%, said Harrison. He would expect pressure on Amgen shares given the perception negative, though he still thinks initial Aimovig demand is robust, Harrison tells investors. He keeps an Overweight rating and $200 price target on Amgen shares.