Efficacy and safety of brexpiprazole for the treatment of acute schizophrenia in Japan: A 6-week, randomized, double-blind, placebo-controlled study.

AIM: This study aimed to evaluate the efficacy, safety, and tolerability of brexpiprazole compared to placebo in Japanese patients with acute schizophrenia (SCZ).

METHODS

We conducted a 6-week, multicenter, double-blind, placebo-controlled, phase 2/3 study in Japan. Patients with acute SCZ were randomized (1:1:1:1) to receive brexpiprazole 1 mg, 2 mg, 4 mg, or placebo once a day. The primary endpoint was the change from baseline to week 6 in Positive and Negative Syndrome Scale (PANSS) total scores.

RESULTS

In the 459 patients that were randomized, brexpiprazole 2 mg showed a significant improvement versus placebo (treatment difference: -7.32, P = 0.0124), although brexpiprazole 4 mg showed numerical improvements (treatment difference: -3.86, P = 0.1959), and brexpiprazole 1 mg showed only minimal change (treatment difference: -0.63, P = 0.8330). Treatment-emergent adverse events with an incidence of ≥5% and ≥2 times the rate of placebo in the brexpiprazole groups were vomiting, elevated blood prolactin, diarrhea, nausea, and dental caries. Most treatment-emergent adverse events were mild or moderate in severity. There were no clinically significant changes in electrocardiogram parameters, bodyweight, laboratory values, or vital signs in the brexpiprazole groups.

CONCLUSION

Brexpiprazole was efficacious and well tolerated in Japanese adult patients with acute SCZ.