Optimizing Treatment of Schizophrenia: Clinical and Economical Potential for Patient Switching to Long-Acting Injectables

INTRODUCTION: Long-acting injectable antipsychotics (LAIs), due to a lower frequency of administration, could address the well-established challenge of non-adherence to oral ones. We conducted a Network Meta-Analysis (NMA) to assess the relationship between administration frequency and effectiveness. The recent introduction of a semi-annual paliperidone palmitate formulation, along with the arrival of monthly paliperidone generics, could emphasize LAI's advantages. Aim of this paper is to present the results derived from an updated version of our previous NMA. These results are used to fuel a budget impact model built to evaluate the economic implications of optimizing dosing intervals. METHODS: We compare the current distribution of patients among available LAI active substances and dosing frequencies with an optimized scenario. In this scenario, 20% of patients are switched to the next permitted regimen with a longer inter-dosing interval. Drug acquisition costs and relapse management costs are taken into account over a one-year simulation period; these last items are estimated by means of the event rates obtained from the updated meta-analysis. The optimized scenario incorporates the reduced cost resulting from the expiration of patents. RESULTS: Throughout the analysis, a total of 11,600 patients were able to switch from shorter to longer dosing intervals, leading to an overall optimization of quality of care. The greater expenditure incurred by the Italian National Health Service (NHS) in the acquisition of newer and longer-lasting drugs is offset by savings associated with the arrival of generics of monthly paliperidone palmitate and the shift toward less-relapsing regimens. The net impact on the NHS budget is a saving of more than 19 million Euros. CONCLUSION: This economic saving has the potential to initiate a virtuous process: it could be reinvested to fund a further shift from oral daily therapies, which are less expensive but marked by poor compliance, to LAIs. According to our simulation, nearly 40 thousand patients could undergo this transition, without additional expenses for the NHS.