Effect of Brexpiprazole on Prolactin and Sexual Functioning An Analysis of Short- and Long-Term Study Data in Major Depressive Disorder

Purpose/Background Evidence supports use of adjunctive atypical antipsychotics in major depressive disorder (MDD). Impaired sexual functioning is common in MDD and may be worsened by antipsychotic adverse effects. We evaluated the effect of brexpiprazole on prolactin and sexual functioning in patients with MDD. Methods/Procedures In short-term studies, patients received adjunctive brexpiprazole 1, 2, or 3 mg or placebo. The long-term study was a flexible-dose (0.5-3 mg/d) open-label extension (OLE). Change from baseline and shifts in prolactin status and prolactin-related treatment-emergent adverse events (TEAEs) were assessed. Sexual functioning was assessed by the Massachusetts General Hospital Sexual Functioning Questionnaire. Findings/Results Median changes in prolactin levels from baseline to week 6 in short-term studies were as follows: brexpiprazole, 5.99 ng/mL (females) and 1.61 ng/mL (males); placebo, -0.15 ng/mL (females) and -0.08 ng/mL (males). Median changes from baseline to week 52 in the OLE were as follows: 0.27 ng/mL (females) and 0.27 ng/mL (males). Prolactin levels in patients with baseline prolactin greater than 1x upper limit of normal values tended to decrease over time. The proportion of brexpiprazole-treated patients with greater than 3x upper limit of normal postbaseline prolactin values in short-term studies for both sexes was low (0%-0.3%) and did not differ from placebo: OLE, 0.5% (females) and 0.8% (males). In short-term studies, the incidence of prolactin-related TEAEs was 3.1% for brexpiprazole and 0.7% for placebo (OLE, 3.1%). There were overall numerical improvements from baseline in sexual functioning for females and males after short- and long-term brexpiprazole treatment, with statistically significant improvements for brexpiprazole versus placebo in females on the items 'interest in sex' (-0.19; 95% confidence interval [CI], -0.33 to -0.05; P = 0.0074), 'sexually aroused' (-0.17; 95% CI, -0.30 to -0.03; P = 0.0154), and 'overall sexual satisfaction' (-0.16; 95% CI, -0.30 to -0.03; P = 0.0184). Implications/Conclusions There were small changes in prolactin levels, low proportions of patients with postbaseline elevated prolactin values, low incidences of prolactin-related TEAEs, and modest improvements in sexual functioning with adjunctive brexpiprazole in MDD.