A 1-Year Double-Blind Study of 2 Doses of Long-Acting Risperidone in Stable Patients With Schizophrenia or Schizoaffective Disorder

George M. Simpson, M.D.; Ramy A. Mahmoud, M.D.; Robert A. Lasser, M.D.; Mary Kujawa, M.D.; Cynthia A. Bossie, Ph.D.; Ibrahim Turkoz, M.S.; Steven Rodriguez, M.S.; and Georges M. Gharabawi, M.D.

Objective: This study examined the effects of 2 doses of long-acting risperidone injection in patients with schizophrenia or schizoaffective disorder.

Method: This 52-week, prospective, randomized, double-blind, multicenter, international study included clinically stable outpatients with schizophrenia or schizoaffective disorder (DSM-IV criteria). Settings included physicians' offices and clinics. Patients received a fixed dose of long-acting risperidone (25 or 50 mg) every 2 weeks. Primary outcome was time to relapse, defined as either rehospitalization or other exacerbation criteria. Other assessments included the Positive and Negative Syndrome Scale, Clinical Global Impressions-Severity of Illness scale, and functional and quality-of-life measures. Safety was assessed via treatment-emergent adverse events, laboratory tests, and movement disorder rating scales. Data were collected from December 2002 to September 2004.

Results: A total of 324 patients were randomized to 25 mg (N = 163) or 50 mg (N = 161) of long-acting risperidone. Time to relapse was comparable (p = .131) for both groups. Projected median time to relapse was 161.8 weeks (95% CI = 103.0 to 254.2) with 25 mg and 259.0 weeks (95% CI = 153.6 to 436.8) with 50 mg. One-year incidences of relapse were 21.6% (N = 35) and 14.9% (N = 24), respectively (p = .059). Psychiatric hospitalization was the reason for relapse for 16 (10%) in the 25-mg group and 10 (6%) in the 50-mg group. Patients experienced statistically significant but modest improvements at endpoint in most measures (i.e., psychotic symptoms, functioning, movement disorder severity) with both doses, with no significant between-group differences.

Conclusion: In this 1-year study, long-acting risperidone was associated with low relapse and rehospitalization rates, indicating that doses of 25 to 50 mg are appropriate for long-term treatment in schizophrenia.

Clinical Trials Registration: ClinicalTrials.gov identifier NCT00297388.

(J Clin Psychiatry 2006;67:1194-1203)

Received April 4, 2006; accepted June 26, 2006. From the Department of Psychiatry, Keck School of Medicine of the University of Southern California, Los Angeles (Dr. Simpson); Medical Affairs, Janssen Pharmaceutica, Inc., Titusville, N.J. (Drs. Mahmoud, Kujawa, Bossie, and Gharabawi and Mr. Rodriguez); Johnson & Johnson Pharmaceutical Services, LLC, Raritan, N.J. (Dr. Lasser); and Quantitative Methodology, Ortho-McNeil Janssen Scientific Affairs, LLC, Titusville, N.J. (Mr. Turkoz).

Supported by Janssen, L.P., Titusville, N.J.

Dr. Simpson has received grant/research support from AstraZeneca and Janssen, has received honoraria from Pfizer, and has served on the speakers or advisory boards of Janssen and Pfizer. Drs. Mahmoud, Kujawa, Bossie, and Gharabawi and Mr. Rodriguez are employees of Janssen and are stock shareholders in Johnson & Johnson. Dr. Lasser is an employee of and stock shareholder in Johnson & Johnson. Mr. Turkoz is an employee of Ortho-McNeil Janssen Scientific Affairs and is a stock shareholder in Johnson & Johnson.

Acknowledgments appear at the end of the article.

Corresponding author and reprints: Georges M. Gharabawi, M.D., Medical Affairs, Janssen Pharmaceutica, Inc., 1125 Trenton-Harbourton Rd., Titusville, NJ (e-mail: GGharaba@JANUS.JNJ.com).