Patients completing studies HPN-100-005 and HPN-100-006 were offered enrollment into one of two 12-month glycerol phenylbutyrate treatment protocols (HPN-100-005SE, HPN-100-007), which required monthly visits that included measurement of fasting ammonia. These protocols also allowed for enrollment of adult and pediatric UCD patients, including all UCD subtypes,

JQ1 purchase who had not completed HPN-100-005 or HPN-100-006. The results of these studies are included for the purposes of pooled analyses. All patients underwent neuropsychological testing at the time of enrollment in HPN-100-005SE or HPN-100-007 and again at study completion. All patients were administered a short form of the WASI (Wechsler Abbreviated Scale of Intelligence) to estimate intellectual ability. Pediatric patients were also assessed by two parent questionnaires: the CBCL (Child Behavior Checklist) to evaluate internalizing (e.g., mood/anxiety) and externalizing behaviors and the BRIEF (Behavior Rating Inventory of Executive Function) to assess day-to-day executive functioning. The BRIEF consists of several subscales that are combined into two functional domains; the Metacognition Index (MI), which measures cognitive control (e.g., working memory, planning, organization,

etc.) and the Behavioral Regulation Index (BRI), which measures behavioral control (e.g., inhibition, flexibility, emotional control). In KU-60019 addition to WASI, adults were administered the Lafayette Grooved Pegboard test (fine motor skills), California Verbal Learning Test-Second Edition (verbal memory), and digit span test (focused attention and working memory). Hyperammonemic crises were prospectively defined in all protocols as requiring at least one ammonia value over 100 μmol/L plus clinical manifestations compatible with hyperammonemia. All protocols were conducted this website under a U.S. IND and were reviewed and approved by the appropriate Institutional Review Board. A Data Safety Monitoring Board was engaged throughout the studies and reviewed all safety results periodically. All patients or their parents signed

a consent or assent form, which had been approved by local Institutional Review Boards prior to enrollment and initiation of any protocol-specific activities. Forty-six patients were enrolled; 45 received at least one dose of study drug and 44 completed the study and constituted the intention to treat (ITT) population (Table 1). Enrollment began in October of 2009 and follow-up of the last patient was completed in September of 2010. Overall treatment compliance was excellent, with ≥99% of patients being at least 80% compliant with the NaPBA and glycerol phenylbutyrate treatments. The predominance of patients with OTC deficiency in the pivotal study, as well as the entire study population, is generally consistent with the predominance of this UCD subtype in the population at large.9, 10, 14 Patients had been taking an average of 14.