A 26-Week Extension Study of EVP-6124 (Alpha-7 nAChR) as an Adjunctive Pro-Cognitive Treatment in Schizophrenia Subjects on Chronic Stable Atypical Antipsychotic Therapy

Inclusion Criteria: * Completion of the Day 182 visit in a previous 26-week double-blind study (EVP-6124-015 or EVP-6124-016). * Subject has signed informed consent for this extension study, indicating that the subject understands the purpose of and procedures required for the study, before the initiation of any extension study specific procedures. Subjects who are unable to provide informed consent will not be included in the study * No clinically significant changes in the subject's medical status during the participation in EVP-6124-015 or EVP-6124-016. Any significant changes in health care status and their impact on subject eligibility will be reviewed by the investigator and sponsor on a case-by-case basis. * In the opinion of the investigator, the extension treatment is in the best interest of the subject. * Fertile, sexually active subjects (men and women) must use an effective method of contraception during the study. Females and the female partners of male must be surgically sterile (hysterectomy or bilateral tubal ligation), postmenopausal for at least 1 year, willing to practice adequate methods of contraception if of childbearing potential (defined as consistent use of combined effective methods of contraception \[including at least one barrier method\]). Female subjects must have a negative urine pregnancy test predose on Day 1. Exclusion Criteria: * Significant risk for suicidal or violent behavior, as determined by the investigator. Significant risk for suicidal behavior is defined as 1) suicidal ideation as endorsed on items 4 and 5 of the Columbia-Suicide Severity Rating Scale (C-SSRS); 2) suicidal behaviors detected by the C-SSRS; or 3) psychiatric interview and examination. * Adverse events from the previous study (EVP-6124-015 or EVP-6124-016) that have not resolved, are of moderate or greater severity and judged to be possibly related or related to study drug and are thought by the investigator to be contraindications to study participation. * Any condition which would make the subject, in the opinion of the investigator, unsuitable for the study. * Female subjects who are pregnant. * Subjects who received any other investigational treatment during participation in either EVP-6124-015 or EVP-6124-016 other than assigned study medication.