AstraZeneca received approval from the FDA for Seroquel for the maintenance treatment of patients with bipolar I disorder, as adjunct therapy to lithium or divalproex. Seroquel is approved by the FDA for the treatment of schizophrenia, and both depressive episodes in bipolar disorder and acute manic episodes associated with bipolar I disorder.
The FDA approval was based on two multicenter, randomized, double-blind, placebo-controlled trials that evaluated Seroquel when used as an adjunct therapy to lithium or divalproex in the maintenance treatment of adult patients with bipolar I disorder. The study design included a 12 to 36 week stabilization phase, which was followed by a longer-term, randomized, double-blind treatment phase that had a mean duration of exposure of 213.2 days for Seroquel and 152.4 days for placebo.
The primary endpoint, which was time to recurrence of a depressive, manic, or mixed mood event, was significant for Seroquel compared with placebo in both studies. Study results indicated that patients treated with Seroquel plus lithium-or-divalproex had a risk reduction of 70% relative to those treated with placebo plus lithium-or-divalproex for time to recurrence of a mood event. This reduction in risk was significant for both recurrence of manic episodes and depressive episodes. The proportion of patients who relapsed when treated with Seroquel was 19% versus 50% of patients on placebo.