Successful switching of patients with acute schizophrenia from another antipsychotic to brexpiprazole: comparison of clinicians' choice of cross-titration schedules in a post hoc analysis of a randomized, double-blind, maintenance treatment study

Abstract

Objective: To compare the tolerability and efficacy of different antipsychotic cross-titration schedules, using data from a brexpiprazole study (Equator; NCT01668797).

Methods: Patients with schizophrenia were cross-titrated from other antipsychotics to brexpiprazole monotherapy in a 1-4 week open-label conversion phase, then entered a single-blind brexpiprazole treatment phase. Patients were stratified into four "conversion groups," according to the amount of time spent in the conversion phase. Discontinuation rates, treatment-emergent adverse events (TEAEs), and efficacy (Positive and Negative Syndrome Scale [PANSS]) were compared between conversion groups.

Results: Of the 404 patients treated with brexpiprazole, the majority (72.0%) spent 22-33 days in the conversion phase. Discontinuation rates due to lack of efficacy or adverse events were low in all conversion groups. Of the 292 patients who successfully switched and completed 8 weeks of brexpiprazole treatment, most were converted to brexpiprazole over 22-33 days (80.1%), and fewer were converted over 1-7 days (2.4%), 8-14 days (6.5%), or 15-21 days (11.0%). The incidence of TEAEs over 8 weeks was lower among those converted over 22-33 days (44.4%) than in other conversion groups (62.5-84.2%), although low patient numbers with shorter conversion times limit the generalizability of this finding. Each conversion group showed comparable improvement in PANSS total score from baseline.

Conclusion: The majority of patients were cross-titrated to brexpiprazole over a period of 22-33 days, by investigators' choice. Additional data on shorter conversions may help clinicians to choose a switching paradigm that best meets their patients' needs.

Keywords: Antipsychotic; brexpiprazole; cross-titration; schizophrenia; switching.