INTERIM REPORT OF A POST-MARKETING SURVEILLANCE OF PALIPERIDONE PALMITATE 3-MONTH FORMULATION IN JAPANESE PATIENTS WITH SCHIZOPHRENIA
Authors: Marumoto *Tatsuro , Saga Yosuke , Kinoshita Hiroaki , Morita Natsuko , Touma Tokiko , Wakamatsu Shinya , Takebe Kyoko , Wakamatsu Akihide , Chiang Chih-Lin 
Published: February 2025

Abstract

Background
Paliperidone palmitate 3-monthly formulation (PP3M) is a long-acting antipsychotic launched in Japan in November 2020. The efficacy and safety of PP3M in patients with schizophrenia were confirmed in the two previous phase III clinical trials (Berwaerts et al., 2015; Savitz et al., 2016). However, the data of efficacy and safety under clinical practice setting is limited.

Aims & Objectives
To evaluate the safety and treatment continuation rate of PP3M in clinical practice settings and gain insight into its practical treatment utilization.

Method
The study enrolled patients from November 2020 to November 2022 in patients started on PP3M according to the dosage and administration in the package insert. For patients enrolled within the first year from the product launch, the observation period extended up to 18 months from the initiation of treatment. For patients enrolled after the first year of following the product launch, the observation period was up to 12 months from the initiation of treatment. All candidates were informed the content of the study, and only those patients who gave their consent were enrolled in the study. Of the 990 patients enrolled from November 2020 to June 2023, 585 patients were analyzed as an interim analysis. The incidence of side effects, PP3M treatment continuation rate, reason for hospital visit, baseline employment status, and concomitant psychotropic medication use were calculated. Of the 585 patients, 350 (59.8%) were male, and the mean age (± standard deviation) was 50.3 (± 13.8) years. The mean duration of disease was 15.8 (±13.5) years in 276 patients. Forty-four percent of patients were working, attending school, or attending day care at the time of switching from PP1M to PP3M.The average observation period was 268 days. Among the 585 patients, 36 patients (6.2%) reported at least 1 side effect. The incidence of side effects was 36 (6.2%) out of 585 patients, and the side effects reported in over 0.5% of patients were schizophrenia (10 patients, 1.7%), hyperprolactinemia (7 patients, 1.2%), and oculogyric crisis(3 patients, 0.5%). Serious side effects were reported in 10 patients (1.7%), including schizophrenia (5 patients, 0.9%), hyperprolactinemia, anxiety,, insomnia, and (1 patient, 0.2%) respectively. Kaplan-Meier survival analysis showed that the estimated treatment continuation rate for PP3M at Day 300 was. Regarding hospital visits, among the 580 patients with multiple PP3M injections, 232 patients (60%) had a visit for a purpose other than PP3M injection.

Discussion & Conclusion
The safety profile of PP3M, as demonstrated in the interim report of the Japan PMS study, was consistent with the safety findings from the global clinical trials. Notably, the treatment continuation rate of PP3M in clinical practice settings in Japan exceeded 90% during the observation period leading up to this interim analysis., it is essential to emphasize that these findings require validation through the final analysis of the PMS study. Patients' baseline clincial characteristics and follow-up duration at the time of interim analysis should be described. Pituitary tumor - is it a prolactinoma, or other type of tumor? (Prolactinoma may be considered a serious consequence of hyperprolactinemia.) Do we have the actual estimated %?Not sure what n=246 means here. Please reword this - unclear what this means

References
Berwaerts, J., Liu, Y., Gopal, S., Nuamah, I., Xu, H., Savitz, A., Coppola, D., Schotte, A., Remmerie, B., Maruta, N., &Hough, D. W. (2015). Efficacy and Safety of the 3-Month Formulation of Paliperidone Palmitate vs Placebo for Relapse Prevention of Schizophrenia: A Randomized Clinical Trial. JAMA psychiatry, 72(8), 830–839. https://doi.org/10.1001/jamapsychiatry.2015.0241
Savitz, A. J., Xu, H., Gopal, S., Nuamah, I., Ravenstijn, P., Janik, A., Schotte, A., Hough, D., &Fleischhacker, W. W. (2016). Efficacy and Safety of Paliperidone Palmitate 3-Month Formulation for Patients with Schizophrenia: A Randomized, Multicenter, Double-Blind, Noninferiority Study. The international journal of neuropsychopharmacology, 19(7), pyw018. https://doi.org/10.1093/ijnp/pyw018