October 22, 2008

Looking at the Efficacy and Safety of Extended Release Paliperidone (INVEGA) for Schizophrenia: A 6-Week Randomized Control Trial and a 52-Week Open-Label Extension

Principal Investigator: Herbert Meltzer, PhD

Centerstone was part of a phase 3 study sponsored by Johnson and Johnson, the makers of paliperidone ER (extended release). Phase 3 studies are relatively large studies, usually involving 300-400 patients at 30 sites, to obtain definitive information about safety and efficacy. Both the 6-week and the 52-week trials showed that paliperidone ER was, overall, both effective and safe for the treatment of schizophrenia. This, plus a second study of similar design,enabled Paliperidone ER to be approved by the FDA in 2007. It is preferred by some to risperidone, which it is closely related to, because in this formulation there are fewer side effects.

The two Phase 3 trials showed that there was a significant increase in social functioning and a decrease in symptoms of schizophrenia for patients taking paliperidone ER.  The side effects for paliperidone ER were more mild than most atypical or typical antipsychotics, and none of the people studied developed seizures. (Johnson & Johnson, 2006).

After this study was completed, several researchers looked at these results combined with several other open-label extensions of paliperidone ER trials and found that patients on paliperidone ER were twice as likely to be able to obtain employment (Janicak, Wu & Amatniek, 2007). They also found that patients on paliperidone ER had significantly less hospitalizations than they did while on other antipsychotic medications (Janicak, Wu & Mao, 2008). The savings in reduced hospitalization days was an annual average of $5951 per person (Janicak, Wu & Mao, 2008). 

References
Johnson & Johnson (2006, June 13). A randomized, double-blind, placebo- and active-controlled parallel-group, dose-response study to evaluate the efficacy and safety
of two fixed dosages of extended release OROS® paliperidone (6 and 12 mg/day) and olanzapine (10 mg/day), with open-label extension, in the treatment of subjects with schizophrenia.

Janicak, P., Wu, J.H., & Amatniek, J. (2007). Changes in mental health resource use after initiation of paliperidone ER in patients with schizophrenia, presented at the 161st Annual Meeting of the American Psychiatric Association (APA), Washington, D.C.

Janicak, P., Wu, J.H., & Mao, L. (2008). Hospitalization rates before and after initiation of paliperidone ER in patients with schizophrenia: results from open-label extensions of the US double-blind trials. Current Medical Research and Opinion. 24(6): 1807-1815.