Pharmacokinetics and Pharmacodynamics (PK/PD) of CEP-26401 in Healthy Subjects

Inclusion Criteria: 1. The subject is able to give legal informed consent and understand the requirements of the study and communicate with the investigator in the local spoken language. 2. The subject is willing to comply with the study requirements (eg, all dietary, exercise, tobacco, and alcohol restrictions) and provide their written informed consent to participate in the study. 3. The subject is a man or woman, 18 to 50 years of age, inclusive. 4. The subject has a body mass index (BMI) of 18.0 to 30.0 kg/m2, inclusive. 5. The subject has skin type I to IV (very light to olive). 6. The subject is in a good health as determined by medical history, ECG, vital signs, physical examination, and clinical laboratory tests. 7. Female subjects of childbearing potential must have a negative serum β-human chorionic gonadotropin (hCG) test (at screening) and check-in and be willing and able to use one of the protocol-specified double-barrier methods of birth control. 8. The subject is able to complete the screening process within 4 weeks prior to study drug administration. Exclusion Criteria: 1. The subject has a cognitive performance outside of reference values at screening. 2. The subject smokes, is a tobacco user, currently uses nicotine products. 3. The subject has a known hypersensitivity to donepezil, modafinil, irdabisant, or one of the excipients, or has any significant food or drug allergies. 4. The subject is a female who is pregnant or lactating. 5. The subject has an intraocular pressure greater than 22 mm Hg. 6. The subject is suffering from, or has a clinically significant history of one or more of the following: cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, neurological, immunological, or psychiatric disorder(s), or a history of any illness that, in the opinion of the investigator, might pose additional risk to the subject by participation in the study or confound the results of the study. 7. The subject has a laboratory abnormality judged by the investigator as clinically significant, or measurements outside of the defined range * Other exclusion criteria apply; please contact the investigator for more information.