Quetiapine Sustained Release Schizophrenia Data Show Relapse Prevention

AstraZeneca today announced clinical trial data presented at the European Congress of Psychiatry (ECP) in Madrid that found the once-daily quetiapine sustained-release formulation treatment effective and well tolerated in patients with schizophrenia. The trial results presented demonstrated that the quetiapine sustained release formulation significantly improved symptoms associated with schizophrenia and reduced the time to psychiatric relapse.

Quetiapine sustained release formulation is under review by regulatory authorities around the world for the treatment of schizophrenia and has not yet been approved in any market.A randomized, double-blind study of 588 patients with acute schizophrenia (Study 132) compared quetiapine sustained release formulation (400 mg/day, 600 mg/day or 800 mg/day) with placebo and found a significant improvement in Positive and Negative Syndrome Scale (PANSS) total scores from baseline for all doses. After 6 weeks of treatment, reductions of 24.8 (p=0.03), 30.9 (p<0.001), and 31.3 (p<0.001) points were seen with 400, 600, and 800 mg doses, respectively, compared with a reduction of 18.8 points for placebo. Patients on quetiapine (600 & 800mg/day) sustained release formulation also had significantly better scores on the Clinical Global Impression (CGI)-Severity scale and significantly more patients showed improvement on the CGI-Improvement scale compared to placebo.A second randomized, double-blind placebo controlled study (Study 004) examined psychiatric relapse in 197 patients with clinically stable schizophrenia treated with either quetiapine sustained release formulation (mean dose 669 mg/day) or placebo. Patients treated with quetiapine sustained release formulation experienced a significantly reduced risk of relapse (risk reduction of 87%, p<0.0001), and a significantly longer time to relapse, compared with those on placebo. Treatment effectiveness was large enough to require the study to be stopped early, in accordance with the study protocol. In the quetiapine sustained release group, the estimated risk of relapse after 6 months was 14.3% versus 68.2% in the placebo group (p<0.001). Hospitalization due to worsening of schizophrenia was required by 8.3% of patients on placebo, but was not needed for any patients taking quetiapine sustained release formulation.Professor Mohan George of the Queen Elizabeth Psychiatric Hospital Birmingham: "In these studies quetiapine sustained release formulation was effective as a once-daily treatment for both acute and clinically stable schizophrenia. Patients responded well to doses between 400 and 800 mg. It is worth noting that a greater separation on endpoints was seen at 600 and 800mg in study 132, and the average dose in study 004 was 669mg/day. In mental healthcare, a choice of formulations is vitally important to provide doctors and patients with additional flexibility and choice of treatment administration."In both studies, somnolence and dizziness were the most common adverse events with quetiapine sustained release formulation and these were generally mild or moderate, transient, and did not generally lead to withdrawal from the trials. The incidence of extrapyramidal adverse events was similar to placebo (EPS-related adverse events were seen in 5.1% of patients taking placebo versus 2.7% [400mg], 8.0% [600mg] and 4.1% [800mg] of patients taking quetiapine sustained release formulation in the acute study.Other new quetiapine sustained release formulation studies presented at the congress show that patients who are inadequately treated with another antipsychotic agent, can be effectively switched to quetiapine sustained release formulation. Among patients who switched to quetiapine sustained release formulation from other antipsychotics, 62.8% achieved improved clinical benefit regardless of the reason for switching (insufficient efficacy or intolerability).(Source: European Congress of Psychiatry : Queen Elizabeth Psychiatric Hospital Birmingham : April 2007.)