Randomized, Double-Blind, Placebo-Controlled Study of Encenicline, an α7 Nicotinic Acetylcholine Receptor Agonist, as a Treatment for Cognitive Impairment in Schizophrenia

Neuropsychopharmacology. 2015 Dec;40(13):3053-60. doi: 10.1038/npp.2015.176. Epub 2015 Jun 19.

Abstract

Encenicline is a novel, selective α7 nicotinic acetylcholine receptor agonist in development for treating cognitive impairment in schizophrenia and Alzheimer's disease. A phase 2, double-blind, randomized, placebo-controlled, parallel-design, multinational study was conducted. Patients with schizophrenia on chronic stable atypical antipsychotics were randomized to encenicline 0.27 or 0.9 mg once daily or placebo for 12 weeks. The primary efficacy end point was the Overall Cognition Index (OCI) score from the CogState computerized battery. Secondary end points include MATRICS Consensus Cognitive Battery (MCCB) (in US patients), the Schizophrenia Cognition Rating Scale (SCoRS) total score, SCoRS global rating, and Positive and Negative Syndrome Scale (PANSS) total and subscale and cognition factor scores. Of 319 randomized patients, 317 were included in the safety population, and 307 were included in the intent-to-treat population. Notable trends in improvement were demonstrated across all cognition scales. For the OCI score, the LS mean difference for encenicline 0.27 mg vs placebo was significant (Cohen's d=0.257; P=0.034). Mean SCoRS total scores decreased showing improvement in function over time, and the difference was significant for encenicline 0.9 mg vs placebo (P=0.011). Furthermore, the difference between encenicline 0.9 mg and placebo was significant for the PANSS Cognition Impairment Domain (P=0.0098, Cohen's d=0.40) and for the PANSS Negative scale (P=0.028, Cohen's d=0.33). Treatment-emergent adverse events were reported at similar frequencies across all treatment groups (39.0% with placebo, 23.4% with encenicline 0.27 mg, and 33.3% with encenicline 0.9 mg). Overall, encenicline was generally well tolerated and demonstrated clinically meaningful improvements in cognition and function in patients with schizophrenia.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Antipsychotic Agents / therapeutic use
  • Cognition / drug effects
  • Cognition Disorders / drug therapy*
  • Cognition Disorders / physiopathology
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nicotinic Agonists / adverse effects
  • Nicotinic Agonists / therapeutic use
  • Psychiatric Status Rating Scales
  • Psychotropic Drugs / adverse effects
  • Psychotropic Drugs / therapeutic use*
  • Quinuclidines / adverse effects
  • Quinuclidines / therapeutic use*
  • Schizophrenia / drug therapy*
  • Schizophrenia / physiopathology
  • Schizophrenic Psychology
  • Thiophenes / adverse effects
  • Thiophenes / therapeutic use*
  • Treatment Outcome
  • Young Adult
  • alpha7 Nicotinic Acetylcholine Receptor / agonists*
  • alpha7 Nicotinic Acetylcholine Receptor / metabolism

Substances

  • Antipsychotic Agents
  • N-(7-chloro-N-quinuclidin-3-yl)benzo(b)thiophene-2-carboxamide
  • Nicotinic Agonists
  • Psychotropic Drugs
  • Quinuclidines
  • Thiophenes
  • alpha7 Nicotinic Acetylcholine Receptor