H.C. Wainwright analyst Andrew Fein thinks Acadia Pharmaceuticals' top-line data release yesterday provided supportive evidence for pimavanserin's potential as an adjunctive therapy for major depressive disorder. However, he points out two major concerns from the study that he believes could shape this program's risks. Although the study hit primary endpoint of change in HAMD-17 score from baseline in stage 1 and in combined analysis, there was no significant benefit observed with pimavanserin treatment versus placebo in stage 2 of the study, Fein tells investors in a research note titled "Trick or Treat? Stage 1 Results Outweigh Stage 2 Miss, In Our View." This result naturally raises the question whether the treatment effect was indeed real rather than an artifact, says the analyst. And second, Fein points out that there has not been any drug approved by the FDA using a sequential parallel comparison design. This, he believes, would add to the regulatory risk of the program, given that the Phase 3 trial would be similar in design to the Clarity trial, per management. Fein has a Buy rating on Acadia with a $60 price target.