Schering-Plough has announced that the investigational agent Saphiris (asenapine) has shown good results as a treatment for patients with predominant, persistent negative symptoms of schizophrenia over a one-year trial.

During the 26-week extension of a randomised, double-blind, multicentred, multinational 26-week clinical trial, the efficacy and safety of Saphiris was compared to olanzapine as a treatment for negative symptoms of schizophrenia.

In the study, Saphiris was shown to be significantly more effective than olanzapine in the reduction of negative symptoms as measured by change from baseline to Day 365 in the negative symptom assessment scale (NSA-16) total score, the primary endpoint of the study.

Negative symptoms of schizophrenia include apathy, lack of emotion and poor social functioning.

Schering-Plough Research Institute vice-president, global clinical research, central nervous system Armin Szegedi said that these symptoms are among the most difficult to treat in the schizophrenia spectrum.

“Few studies with the antipsychotics available on the market have been designed specifically to evaluate long-term effects on predominant, persistent negative symptoms. The results from this large clinical study programme will provide new insights into potential treatment of these symptoms,” Szegedi said.

These large Phase III studies were conducted following a previous Phase II study where favourable data on negative symptoms were observed for asenapine.