Real-World Evidence of Brexpiprazole Use and 6-Month Mortality, Hospitalization, and Emergency Department Visits Among Persons With Dementia.

Background and objectives: Alzheimer disease and other dementias are accompanied by depression and agitation and other behavioral and neuropsychiatric symptoms. In 2023, brexpiprazole became the first antipsychotic approved by the US Food and Drug Administration to treat agitation in persons with Alzheimer disease, but, like all atypical antipsychotics, it includes a black box warning of an increased risk of mortality among persons with dementia. This study provides real-world evidence of mortality in a heterogeneous sample of brexpiprazole users to understand effects in the population.

Methods: We used a 100% sample of Medicare claims data Parts A, B, and D from 2014 to 2023. Our sample was limited to beneficiaries with diagnosed dementia, who were continuously enrolled for at least 2 years and were new users of the atypical antipsychotics brexpiprazole or aripiprazole in a given year. We used matching and logistic regression to estimate the relationship between incident use of brexpiprazole, compared with aripiprazole, and mortality, emergency department (ED) visits, and hospitalization within 6 months.

Results: Among the 41,871 beneficiaries with dementia, 71.7% of brexpiprazole and 69.7% of aripiprazole users were women with a mean age of 75.7 and 78.0 years, respectively. Among persons living with dementia (PLWD), 6-month mortality was statistically lower among new users of brexpiprazole based on estimates from logistic regression and a matched sample of new users of brexpiprazole or aripiprazole (OR 0.49, [95% CI 0.37-0.65]).There was no statistical difference between the incident use of brexpiprazole and aripiprazole use for ED visits or hospitalization within 6 months of use initiation. Adjustment for potential unobserved confounding used two-stage least squares estimation and found no statistically significant differences in six-month mortality, ED visits, or hospitalizations between the 2 groups.

Discussion: Brexpiprazole use is not associated with differential mortality risk compared with aripiprazole use among PLWD. Brexpiprazole offers a treatment option which is important given the heterogeneity of effects of antipsychotics on persons. A two-stage least squares method is used to eliminate bias on estimates because of observed and unobserved differences between the 2 groups, but the small sample size is a limitation.

Classification of evidence: This study provides Class III evidence that brexpiprazole does not increase the risk of mortality at 6 months compared with aripiprazole in PLWD.