Otsuka Pharmaceutical Co., Ltd.

April 20, 2015

Results of Phase III Study of Brexpiprazole in Adult Patients with Schizophrenia Published in American Journal of Psychiatry

  • Brexpiprazole demonstrated statistically significant efficacy vs. placebo in PANSS (Positive and Negative Syndrome Scale) Total Score in adult patients with schizophrenia.*1
  • Brexpiprazole is a serotonin-dopamine activity modulator (SDAM). Brexpiprazole is a partial agonist at 5-HT1A and dopamine D2 receptors at relatively equal potency, an antagonist at 5-HT2A and an antagonist at noradrenaline alpha1B/2C receptors.*2
  • At least 21 million people in the world are estimated to be affected by schizophrenia, including 2.4 million adults in the U.S.*3,*4

Results from a multicenter study evaluating the effects of the investigational compound brexpiprazole, as monotherapy in adult patients with schizophrenia, were published today online by the American Journal of Psychiatry.*1 The study, "Efficacy and Safety of Brexpiprazole for the Treatment of Acute Schizophrenia: A 6-Week, Randomized, Double-Blind, Placebo-Controlled Trial" evaluated the efficacy and tolerability of brexpiprazole in adult patients with an acute exacerbation of schizophrenia. The results will be featured in the September 2015 print issue of the publication.

"Schizophrenia is a complicated disease and while advances have been made, patients often still lack an effective treatment path," said Dr. Christoph U. Correll, Professor of Psychiatry, Hofstra North Shore LIJ School of Medicine and Medical Director, Recognition and Prevention Program (RAP), The Zucker Hillside Hospital, both in New York, and lead investigator of the study. "It is important for clinicians and patients to have a range of treatment options to manage symptoms, and the publication of these data helps increase awareness of the potential of brexpiprazole in this patient population."

Study Results*1

The Phase III trial randomized 636 patients with acute schizophrenia to fixed doses of brexpiprazole (0.25 mg, 2 mg or 4 mg) or placebo (randomized 1:2:2:2), respectively, for 6 weeks. The results indicated that brexpiprazole 2 mg and 4 mg demonstrated significant improvement versus placebo in the primary endpoint of change from baseline to Week 6 in PANSS (Positive and Negative Syndrome Scale) Total Score (0.25 mg: -14.90; 2 mg: -20.73, p=<0.0001; 4 mg: -19.65, p=0.0006 vs. placebo -12.01).

Key secondary endpoint result, the change in CGI-S (Clinical Global Impression-Severity Scale) score at Week 6, supported the primary results (0.25 mg: -0.85; 2 mg: -1.15, p=0.006; 4mg: -1.20, p=0.002 vs. placebo -0.82). Improvements (p<0.05) from baseline to Week 6 in the 2 mg and 4 mg groups compared to placebo were seen in the following secondary efficacy endpoints: PANSS positive and negative subscales, PANSS Excited Component score and PANSS Marder factor scores relating to positive and negative symptoms, disorganized thought and uncontrolled hostility/excitement.

Overall, approximately 65% of patients completed the 6-week study. Discontinuations due to adverse events were 13.3%, 8.2%, 9.4%, and 17.4%, while discontinuations due to lack of efficacy were 8.1%, 9.4%, 3.9% and 10.1% in the brexpiprazole 0.25 mg, 2 mg, 4 mg and placebo groups, respectively.

The most frequently reported treatment-emergent adverse events (TEAEs; greater than 5% in at least one brexpiprazole treatment arm and more frequent than placebo) were diarrhea (5.6%, 1.6%, 3.9% vs. 1.6%), nausea (1.1%, 5.5%, 3.3% vs. 4.3%), akathisia (0%, 4.4%, 7.2% vs. 2.2%) and headache (10.0%, 9.3%, 12.2% vs. 8.2%) in the brexpiprazole 0.25 mg, 2 mg, 4 mg versus placebo groups, respectively.

Other activating (restlessness, insomnia, anxiety) and sedating (somnolence, fatigue, sedation) treatment-emergent adverse events were reported with a similar or lower incidence in patients receiving brexpiprazole compared with those receiving placebo. There were no clinically significant effects on low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG) and total cholesterol (TC).

Otsuka and Lundbeck initially presented results from this pivotal Phase III study evaluating the effects of brexpiprazole as monotherapy in adult patients with schizophrenia at the 53rd Annual Meeting of the American College of Neuropsychopharmacology (ACNP) in December 2014.

About Brexpiprazole (OPC-34712)

Brexpiprazole is a novel investigational psychotropic compound discovered by Otsuka and under co-development with Lundbeck. A New Drug Application for brexpiprazole has been filed with the U.S. Food and Drug Administration (FDA) and the PDUFA date is July 2015 (PDUFA date).

About Schizophrenia

At least 21 million people worldwide are estimated to be affected by schizophrenia, including approximately 2.4 million adults in the U.S*3,*4 Schizophrenia symptoms usually start to appear between ages 16 and 30.*5


  1. 1Correll, C. et al. The American Journal of Psychiatry. Efficacy and safety of brexpiprazole for the treatment of acute schizophrenia: a 6-week randomized, double-blind, placebo-controlled trial. April 2015.
  2. 2Maeda, K. et al. Pharmacological Profile of Brexpiprazole (OPC-24712): a Novel Serotonin-Dopamine Activity Modulator.
  3. 3World Health Organization, Schizophrenia Fact Sheet, 2014. Available at:
  4. 4The National Alliance of Mental Illness, Mental Illness Facts and Numbers. March 2013. Available at:
  5. 5 National Institutes of Mental Health (NIMH). Schizophrenia. Available at: