New data from a six-month open label randomised controlled trial show Invega (paliperidone ER) is associated with significantly less metabolic effects compared to oral olanzapine in people with schizophrenia, while demonstrating comparable efficacy. The results were presented today at the 15th Biennial Winter Workshop in Psychoses in Barcelona, Spain.

Metabolic side effects, including changes in serum lipid levels, glucose levels and weight gain, are a recognised effect of treatment with atypical antipsychotics, and can increase the risk of developing longer-term chronic health conditions such as diabetes and cardiovascular disease.

The primary endpoint of the study was the change over six months in the triglyceride to high density lipoprotein ratio, a sensitive marker for insulin resistance in non-diabetic patients. Results from the intent-to-treat analysis on a total population of 559 patients showed no statistically significant change in the TG:HDL ratio from baseline to endpoint in patients treated with Invega (-0.08 plus or minus 1.10, p=0.47184). In patients treated with oral olanzapine, the TG:HDL ratio significantly increased from baseline to endpoint (0.42 plus or minus 1.19, p<0.0001). As the difference between Invega and olanzapine at endpoint was statistically significant (p<0.0001), the primary endpoint of the trial was met.

"Metabolic changes as a result of antipsychotic treatment are associated with increased health risks such as weight gain and diabetes which in turn can impact on a patient's self-confidence and compliance with medication -significant concerns in what is an already vulnerable patient population," said Dr D J H Niehaus, Flexivest Fourteen Research Centre, Oakdale, Bellville, Cape Town, South Africa. "Minimising treatment-related metabolic effects is an important clinical goal for effective management of schizophrenia, and this study demonstrates that Invega can help meet this need."

The study showed comparable efficacy between Invega and olanzapine in reducing symptoms of schizophrenia, as assessed using the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression Scale (CGI-S). In both treatment groups, PANSS total scores decreased significantly at endpoint (p<0.0001 versus baseline). After intergroup testing, it was concluded that Invega and olanzapine were non-inferior in efficacy as measured by change in PANSS total score. In both treatment groups, a statistically significant improvement in symptoms at six weeks, three and six months and endpoint (p<0.0001) was also reported using the CGI-S.

Invega (paliperidone ER), an atypical antipsychotic medication, was first approved in Europe in June 2007 for the treatment of schizophrenia.

The Janssen-Cilag companies are part of the Johnson & Johnson family of companies. They have a long track record in developing and marketing treatments for central nervous system disorders, pain management, oncology, infectious diseases, reproductive health and gastrointestinal disorders.