Real-life effectiveness of transitioning from paliperidone palmitate 1-monthly to paliperidone palmitate 3-monthly long-acting injectable formulation.

Abstract

Non-adherence to antipsychotics in schizophrenia is associated with an increased risk of psychotic relapse and hospitalization, a risk that is reduced with the use of long-acting injectable (LAI) antipsychotics. Randomized clinical trials (RCTs) have demonstrated the efficacy of paliperidone palmitate 3-monthly (PP3M) for psychotic relapse prevention in schizophrenia, but it remains poorly documented among individuals treated in real-life settings who can benefit the most out of LAIs. The objective of this study was to evaluate the effectiveness of PP3M in relapse prevention among patients with schizophrenia. This is a multicentre retrospective study conducted in four outpatients' clinics across Canada. All consecutive patients with a main diagnosis of schizophrenia who initiated PP3M between June 2016 and March 2020 were included. The primary outcome was psychotic relapse, defined using broad and clinically relevant criteria. Among 178 consecutive patients who were switched to PP3M, the 12-month relapse rate was 18.5% and the relapse-free survival probability was 0.788 (95% confidence interval [CI] = 0.725-0.856). Comorbid diagnoses of personality disorders and substance use disorders were associated with hazard rates (HRs) of 3.6 (95% CI = 1.8-7.3, p < 0.001) and 3.1 (95% CI = 1.6-6.2), respectively. Increased psychopathology severity was associated with an increased likelihood of relapse, while having a job or being in school was protective. These findings reinforce the necessity of conducting research in patients with comorbid psychiatric disorders who are typically underrepresented in RCTs, yet overrepresented in real-life settings, in order to better inform and guide clinical practice.