The International Journal of Neuropsychopharmacology

Research Article

Paliperidone palmitate, a potential long-acting treatment for patients with schizophrenia. Results of a randomized, double-blind, placebo-controlled efficacy and safety study

Michelle Kramera1 c1, Robert Litmana2, David Hougha1, Rosanne Lanea1, Pilar Lima1, Yanning Liua1 and Mariëlle Eerdekensa3

a1 Johnson & Johnson Pharmaceutical Research and Development, L.L.C., Raritan, NJ, USA

a2 Center for Behavioral Health, L.L.C., and Georgetown University Medical School, MD, USA

a3 Johnson & Johnson Pharmaceutical Research & Development, Division of Janssen Pharmaceutica N.V., Beerse, Belgium


We evaluated the efficacy and safety of the investigational long-acting injectable antipsychotic agent paliperidone palmitate (PP) in the treatment of schizophrenia. Patients were randomized to receive gluteal injections of placebo or PP (50 or 100 mg eq., fixed doses), without oral supplementation, on days 1, 8, and 36 (9-wk, double-blind phase) in this phase 2b study. Patients (n=197, intent-to-treat analysis set) were 62% men, mean (s.d.) age 39 (10) yr, with a baseline mean (s.d.) Positive and Negative Syndrome Scale (PANSS) total score of 87.0 (12.5). Mean (s.d.) PANSS total scores showed significant improvement at endpoint (primary measure) for both the PP 50 mg eq. [−5.2 (21.5)] and PP 100 mg eq. [−7.8 (19.4)] groups, vs. placebo [6.2 (18.3)] (p⩽0.001, each dose vs. placebo). This improvement was detected by day 8 and maintained to endpoint (p⩽0.011) for both doses. In the safety analysis set (n=247), fewer PP-treated patients (2%) discontinued for treatment-emergent adverse events vs. placebo-treated (10%). Rates of treatment-emergent extrapyramidal syndrome-related adverse events were comparable between active treatment and placebo, with the exception of parkinsonism-related disorders (50 mg eq. 5%, 100 mg eq. 8%, placebo 1%). Results of other safety measures suggest PP to be generally well-tolerated. Throughout the study, investigators rated injection-site pain as absent (56–71%), mild (24–39%), moderate (2–12%), or severe (0–2%). PP (50 and 100 mg eq. doses) administered as a gluteal intramuscular injection was efficacious and generally tolerated in these patients with acute symptomatic schizophrenia.

(Received March 19 2009)

(Reviewed May 26 2009)

(Revised October 05 2009)

(Accepted October 20 2009)

(Online publication November 27 2009)


c1 Address for correspondence: Dr M. Kramer, 3210 Merryfield Row, San Diego, CA 92121, USA. Tel.: 858 784-3203 Fax: 858 450-2090 Email:


Portions of this paper were presented at the United States Psychiatry and Mental Health Congress, FL, USA, October 2007; and at the Winter Workshop on Schizophrenia and Bipolar Disorders, Montreux, Switzerland, February 2008.