Results Presented from Phase IIb Clinical Study of Merck & Co., Inc. Investigational Insomnia Therapy MK-4305

SAN ANTONIO--(BUSINESS WIRE)--Clinical results from a Phase IIb study showed that MK-4305, Merck's investigational dual orexin receptor antagonist, was significantly more effective than placebo (p<0.005) in improving overall sleep efficiency at night one and at the end of week four in patients with primary insomnia. MK-4305 was generally well-tolerated in the study. Orexins are neuropeptides (chemical messengers) that are released by specialized neurons in the hypothalamus region of the brain and are believed to be an important regulator of the brain’s sleep-wake process. The data were presented for the first time at the SLEEP 2010 24th Annual Meeting of the Associated Professional Sleep Societies.