almorexant in primary insomnia

Conditions: Insomnia; Primary Insomnia

Summary: the aim of the study is to determine the minimum effective dose of act-078573 on sleep efficiency and to assess the effects of different doses of act-078573 on other psg parameters.


Eligibility criteria:
inclusion criteria: * men or women 18 - 65 years of age (inclusive). * women of childbearing potential must have a negative urine pregnancy test at the screening visit, the screening adaptation night, and pre-treatment and use a reliable method of contraception during the entire study duration and for at least 3 months after study drug intake. reliable methods of contraception are: * barrier type devices (e.g., female condom, diaphragm, contraceptive sponge) only in combination with a spermicide. * intra-uterine devices. * oral, injectable, implantable or transdermal contraceptives only in combination with a barrier method. * abstention, rhythm method, and contraception by the partner alone are not acceptable methods of contraception. women not of childbearing potential are defined as prepubescent, postmenopausal (i.e., amenorrhea for at least 1 year), or surgically or naturally sterile. * body mass index (bmi) between 18 and 30 kg/m2 (limits included) at screening visit. * 12-lead ecg without clinically relevant abnormalities at screening visit. * hematology and biochemistry test results not deviating from the normal range to a clinically relevant extent at screening visit and following the screening/adaptation night. * primary insomnia by dsm-iv-tr criteria based on medical history and the assessments performed at screening visit. * history of the following for at least 3 months prior to the screening visit: * usual reported subjective total sleep time (tst) 3 - 6 hours. * usual sleep disturbance with a subjective sleep onset latency of \> 30 min. * daytime complaints associated with poor sleep (e.g., fatigue, irritability, difficulty concentrating). * polysomnography (psg) at screening/adaptation night confirming tst \< 6 h and lps ≥ 20 min. * willingness to refrain from cns-active drugs for 5 half-lives of the respective drug (but at least 1 week) prior to the screening/adaptation night and up to the end of treatment period 2. the usage of short-acting hypnotics (defined as hypnotics with a half-life of up to and including 10 hours) is allowed up to 48 hours prior to each psg night, i.e., prior to the screening/adaptation night and prior to the treatment psg nights. * urine drug test negative for barbiturates, cannabinoids, amphetamines, and cocaine at screening visit 1, screening/adaptation psg night and pre-treatment. urine drug test negative for benzodiazepines and opiates at screening/adaptation psg night and pre-treatment. * signed informed consent prior to any study-mandated procedure. exclusion criteria: * symptom assessment questionnaire (sbb) for diagnosis of apnea resulting in a score \> 2 at screening visit. * zung self-rating depression scale (sds) and/or zung self-rating anxiety scale (sas) resulting in a raw score ≥ 50 at screening visit. * restless legs syndrome and/or meeting all four essential diagnostic criteria for rls (see appendix 10). * insomnia due to sleep apnea or periodic limb movement disorder as assessed by psg at screening/adaptation night: * apnea/hypopnea index (ahi) \> 10/h * periodic limb movement arousal index \> 10/h * major depressive disorder, severe psychosis, or significant anxiety disorder. * pregnancy or breast-feeding. * systolic blood pressure \> 160 mmhg and/or diastolic blood pressure \> 100 mmhg at screening visit. * within the 2-month period prior to the screening visit, clinical evidence of alcoholism or drug abuse. * any known factor or disease that might interfere with treatment compliance, study conduct or interpretation of the results such as psychiatric disease or a disease which may affect the pharmacokinetics of the study drug. * treatment with strong inhibitors of cyp3a4 (e.g., azole derivatives, ritonavir, clarithromycin) within 1 week prior to the screening/adaptation psg night and up to the end of treatment period 2. * excessive caffeine consumption (regular caffeine consumption of \> 7 units per day). * night shift workers. * known hypersensitivity to any excipients of the drug formulation. * planned treatment or treatment with another investigational drug within 1 month prior to randomization and up to the end of treatment period 2. * known concomitant life-threatening disease with a life expectancy \< 24 months. * unstable medical abnormality, significant medical disorder or acute illness. * recruitment of the same patient twice to the same dose level. patients may be recruited to a lower dose level, provided that there are at least 28 days between last study drug administration and screening/adaptation psg night.