Cowen analyst Chris Shibutani says ALKS 3831 "cleared the efficacy bar" for new drug application filing in its first pivotal efficacy study. Importantly, 3831 also demonstrated similar efficacy to the olanzapine comparator arm, Shibutani tells investors in a research note. He expects 3831 to show its differentiated profile of reduced weight gain compared to olanzapine in the second pivotal weight study, expected in mid-2018. The analyst believes last night created some investor confusion, but points out the ENLIGHTEN-1 study was not designed to demonstrate any relative reduction in weight gain with ALKS 3831 versus olanzapine. He keeps an Outperform rating on Alkermes with a $63 price target. The shares in after-hours trading last night dropped 3% to $56.00.