Role of 3-monthly long-acting injectable paliperidone in the maintenance of schizophrenia

Paliperidone palmitate 3-month (PP3M) represents a new long-acting injectable antipsychotic therapeutic option. This review aims: 1) to summarize available data relating to efficacy, safety, tolerability and costs of PP3M; 2) to describe hospitalization rate, occupational status, treatment preference, satisfaction, adherence and caregiver burden of patients with schizophrenia who participate in PP3M clinical trials; 3) to examine ethical implications, pros and cons of PP3M use and 4) to propose study designs to further assess PP3M. On August 21, 2017, a search on PubMed about PPM3, without any filter restriction, was conducted and all available records were analyzed. Records written in a language other than English were excluded. Twenty-two records were included in this review: 6 reviews, 1 report, 4 pharmacokinetic studies, 2 cost-effectiveness analyses, 1 open-label clinical trial, 2 randomized controlled trials (RCTs), 5 studies based on these 2 RCTs and 1 observational study. According to these last 9 studies, when compared with placebo, PP3M showed a longer time to relapse and good safety and tolerability profiles. Furthermore, when compared with paliperidone palmitate 1 month (PP1M), PP3M treatment showed: 1) non-inferiority in terms of efficacy, safety, tolerability, rate of hospitalization, symptomatic and functional remission, treatment preference and variations of the occupational status; 2) a longer time to relapse after treatment discontinuation and 3) a similar reduction of the caregiver burden. PP3M is the only 3-monthly long-acting injectable antipsychotic available on the market. This makes it a unique option of treatment, which could be chosen both in early and advanced phases of illness. Nonetheless, longer naturalistic follow-up studies, two-arm head-to-head superiority trials and mirror studies, based on real-world samples of patients, are needed to further assess long-term safety and advantages of this new option of treatment and to define patients' sub-populations that would most beneficiate from it.