In this trial, Saphris (asenapine) was statistically significantly more effective than placebo in preventing relapse, as measured by the primary endpoint of the trial estimated through Kaplan-Meier curves.
At the 26 week endpoint, 47% of the placebo-treated patients relapsed, compared with only 12% of the asenapine-treated patients (p<0.0001). Asenapine was generally well tolerated, with somnolence and insomnia being the most frequently reported adverse events in the initial open-label treatment phase. The Phase III study was a placebo-controlled, double-blind, clinical trial with a randomized withdrawal design that evaluated the efficacy and safety of sublingually administered asenapine (five or 10mg BID) compared to placebo in the prevention of relapse in patients with schizophrenia. A total of 700 patients entered the open-label treatment with asenapine for up to 26 weeks. Of these, a total of 386 patients met criteria for stabilization on asenapine and were randomized to treatment in the 26-week double-blind placebo-controlled phase of the trial. Thomas Koestler, executive vice president and president of Schering-Plough Research Institute, said: "Asenapine is an important late-stage compound in the Schering-Plough development pipeline, and we are encouraged by the top-line data we are sharing today. We believe that asenapine may have the potential to help relieve the burden of schizophrenia."