Phase III trial data suggest that extended-release paliperidone significantly reduces symptoms of schizophrenia and improves personal and social function, according to presentations made December 14 at a scientific meeting. Discontinuation rates due to adverse events for all dose groups were comparable with rates for placebo.

"The data presented at this meeting offer the medical community its first look at the profile of paliperidone [extended release] ER in the treatment of the clinical symptoms of schizophrenia, and its impact on patients' personal and social functioning," said Stephen Marder, MD, Professor of Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, and author of one of the studies.
Paliperidone ER is the first antipsychotic to use the patented OROS extended-release technology, which provides a steady release of medication over a 24-hour period, leading to minimal peaks and troughs in plasma concentrations. In addition, paliperidone ER is not extensively metabolized by the liver and is excreted largely unchanged through the kidney.

Paliperidone ER demonstrated significant improvements in mean total scores of the Positive and Negative Syndrome Scale (PANSS) versus placebo for all doses tested in both studies. PANSS is a validated, multi-item inventory composed of five factors: positive symptoms, negative symptoms, disorganized thoughts, uncontrolled hostility / excitement, and anxiety / depression.

Paliperidone ER also demonstrated improvements in the Personal and Social Performance scale (PSP) versus placebo in both trials, with statistical significance achieved in four of five paliperidone ER treatment arms. The PSP is a validated, clinician-rated scale that measures personal and social functioning in four domains of behavior -- socially useful activities including work and study, personal and social relationships, self care and disturbing and aggressive behaviors. This is the first time that the PSP scale has been incorporated into a pivotal clinical trial program.

The overall incidence of treatment emergent adverse events pooled across both studies was comparable with the incidence for placebo. Specific adverse events that occurred at a rate of greater than or equal to 5 percent were headache, akathisia, extrapyramidal disorder, sedation, insomnia, agitation, anxiety, tachycardia, and sinus tachycardia for paliperidone ER, and headache, sedation, insomnia, agitation and anxiety for placebo.

The drug is currently under review for possible approval in the USA.