ACADIA Pharmaceuticals Announces Positive Clinical Trial Results Demonstrating That ACP-103 Increases Slow Wave Sleep

ACADIA Pharmaceuticals Inc. has reported top-line results from a proof-of-concept clinical study that assessed the effect of ACP-103 on deep, or slow wave, sleep in healthy older volunteers using polysomnography, PSG. Results of the study demonstrated that ACP-103 induced a robust and statistically significant increase in slow wave sleep that was dose-related. ACP-103 treatment also had a positive impact on measures for sleep maintenance, including decreases in the number of awakenings after sleep onset and in the time awake after sleep onset. ACP-103 is ACADIA's proprietary serotonin 5-HT2A inverse agonist that blocks the activity of this key receptor.

The clinical trial was a double-blind, placebo-controlled study involving 45 healthy volunteers ranging in age from 40 to 64. ACP-103 was safe and well tolerated in the study subjects and there were no serious adverse events reported.

For further information please contact:

Bo-Ragner Tolf,

Vice President

Tel: +46 40 601 3400

Email: btolf@acadia-pharm.com

Or visit: http://www.acadia-pharm.com