JNJ-55308942 is a potent, selective, and brain penetrant antagonist of the adenosine triphosphate (ATP) gated P2X7 receptor. The primary hypothesis that will be tested in this study is that JNJ-55308942, compared to placebo, results in a significant improvement in the reduction of the symptoms of depression in participants with BD in an MDE as assessed by change in Montgomery-Åsberg Depression Rating Scale (MADRS) total score. Efficacy assessment will include MADRS and safety assessment will include physical examination, adverse events, electrocardiogram (ECG), vital signs, clinical safety laboratory assessments, and suicidal ideation and behavior risk monitoring. Total duration of this study will be up to 12 weeks.
The purpose of this study is to evaluate the efficacy of JNJ-55308942 compared to placebo on symptoms of depression in participants with bipolar disorder (BD) in a major depressive episode (MDE) at Week 6.