Many people with schizophrenia struggle to regularly take their prescribed antipsychotics, increasing their risk of experiencing a relapse in symptoms.
It has been estimated that approximately 35% of people with schizophrenia will experience difficulty complying with their prescribed antipsychotic regime, and only 25% will be fully compliant after two years (Bishra, 2010).
Long-acting injectable (LAI) antipsychotics are a therapeutic option available for people who find it difficult to adhere to their prescribed medication regime. Paliperidone palmitate is an LAI formulation of the oral antipsychotic paliperidone (an active metabolite of risperidone) which is administered once a month. It has been shown to have comparable efficacy and tolerability with risperidone LAI, and to cause similar side-effects that include extrapyramidal movement disorders and weight gain (Nussbaum 2012).
The period of time between injections has since been extended, and a three month paliperidone palmitate LAI is currently awaiting recommendation from the Committee for Medicinal Products for Human Use. The intention behind developing a longer interval between doses is to provide fewer opportunities for non-adherence and therefore reduce the risk of relapse (Berwaerts 2015).
A non-inferiority study was therefore conducted to investigate whether the efficacy of three month paliperidone palmitate (PP3M) in treating the symptoms of schizophrenia was not less effective than one month paliperidone palmitate (PP1M) (Savitz 2016).